Can a county board of supervisors take cartography and property-title staff away from the elected county assessor and put them in a department reporting to the board?

Plain-English summary

Yavapai County Attorney Sheila Polk asked the AG a question that came up in a real local dispute: could the county board of supervisors take the cartography and property-title personnel out of the elected county assessor's office and reassign them to a new department that reports to the board?

AG Brnovich answered no, in detail. The opinion runs through about a dozen subquestions but the core conclusion is unitary: the cartography and title functions are necessary to the assessor's statutory duties, the board cannot lawfully strip the assessor of personnel needed to perform those duties, and the board's "review and override" promise doesn't change the analysis.

The reasoning rests on three pillars.

First, the assessor is a constitutional officer with constitutionally and statutorily defined powers. Article 12, §§ 3 and 4 of the Arizona Constitution makes county assessors elected officials with duties "as prescribed by law." A.R.S. §§ 11-541 to 11-543 spell out the assessor's powers, oath, and personal liability for unassessed property due to neglect. The legislature has tasked the assessor with identifying every taxable property in the county "by diligent inquiry and examination" (§ 42-13051(A)).

Second, cartography and title functions are inseparable from the core assessor duty. The Department of Revenue's Assessment Procedures Manual (promulgated under § 42-11054) explicitly identifies maps, plat creation, conveying-document processing, ownership-status maps, parcel numbering, and tax-area-code assignment as core assessor responsibilities. The opinion cites four sprawling footnotes listing dozens of statutes that depend on or relate to the assessor's mapping and title functions: from school district boundaries (§ 15-442(C)) and irrigation district records (§§ 48-262, 48-1594) to delinquent tax sales (§ 42-18111) and underground utility districts (§ 48-620).

Third, the supervisory chain reinforces this. ADOR has general supervisory authority over assessors under § 42-13002. ADOR has no authority over a county board of supervisors. Transferring assessor functions to a board-controlled department would break the supervisory chain and obstruct ADOR's statutory oversight role.

The opinion analogizes to Romley v. Daughton (App. 2010), which held that a county board of supervisors cannot effectively divest the elected county attorney of his authority to represent the county absent a case-specific finding of unavailability or conflict. The same separation-of-powers logic applies here: the board cannot use its budget or personnel authority to functionally eliminate an elected officer's statutory powers.

The "review and override" alternative the board apparently floated, that the assessor could simply review board-department data after entry, doesn't fix anything. Once mapping and title personnel report to the board, the assessor loses the ability to direct how data is gathered, classified, or entered. The "ultimate review" is illusory if the assessor never controlled the work product in the first place.

Currency note

This opinion was issued in 2015. Subsequent statutory amendments, court decisions, or later AG opinions may have changed the analysis. Treat this page as historical context, not current legal advice. Verify current law before relying on any specific rule, deadline, or remedy mentioned here.

Background and statutory framework

The Arizona Constitution treats county assessors as elected, constitutional officers. Article 12, § 3 enumerates the county officers; § 4 leaves their duties and powers to statutory definition. The legislature has given the assessor a specific mandate: identify, locate, value, and document every taxable parcel in the county.

Under § 42-13051, the assessor must "by diligent inquiry and examination" identify all real property subject to taxation by December 15 each year. The assessor must determine the names of all owners, claimants, possessors, or controllers; determine full cash value as of January 1; and list the property on the tax roll.

The assessor must do this using "aerial photography, applicable department of revenue records, building permits and other documentary sources and technology" (§ 42-13051(C)). That list maps directly onto the work that cartographers and title personnel perform.

ADOR's Assessment Procedures Manual breaks out the work into:

• Field surveys
• Processing of conveying documents (affidavits of value, deeds)
• Creation and processing of plat maps (cadastral maps)
• Studying aerial and ground-based photographs
• Processing of building permits
• Analysis of ownership status maps

The Manual is explicit that "a well maintained cadastral mapping system (showing the extent and ownership of land) is essential to provide a standard, accurate legal description, which is needed for the accurate location, identification and inventory of property."

Beyond the assessment-roll core, the assessor's mapping and title outputs feed dozens of other government functions: school district boundary determinations (§ 15-442(C)), special taxing district records (§§ 48-262, 48-1594), notice procedures for underground utility districts (§ 40-344), tax-sale notices to property owners of record (§ 42-18202), and many more. The Premiere RV decision (App. 2009) holds that a parcel split occurs, for tax purposes, only when the assessor completes the identification and valuation process.

The board of supervisors' role is different. Under § 11-251(12)-(13), the board levies and equalizes tax assessments, but does not identify property or perform the prerequisite mapping and title work. Multiple Arizona statutes presume that boards rely on the assessor's records when performing their duties (§§ 40-344, 42-18303).

The Romley v. Daughton precedent is the closest analog. There, the Maricopa County Board of Supervisors decided that the County Attorney had a conflict of interest preventing him from representing the board in most civil matters, and set up a General Litigation Department to take over civil work. The Court of Appeals held that the board could only displace the County Attorney case by case, after specific findings of unavailability or conflict. A blanket reassignment exceeded board authority. The same principle applies to the assessor: a blanket personnel transfer exceeds board authority.

Common questions

Q: Our board of supervisors wants to consolidate GIS staff across multiple county departments into a single GIS bureau. Does this opinion forbid that?
A: The opinion's specific concern is removing personnel necessary to assessor functions from the assessor's control. A shared GIS service that the assessor relies on but does not control would still leave assessor duties unfulfilled. Counties exploring this should ensure the assessor retains direction over assessor-specific cartographic work or risk the same usurpation problem.

Q: Can the board reduce the assessor's budget?
A: Budget authority is different from personnel transfer. Boards have budgetary discretion, but cannot use it to functionally eliminate constitutionally and statutorily mandated assessor functions. The opinion's logic suggests budget cuts that prevent the assessor from performing core duties would face similar legal challenges.

Q: Does this apply to other elected county officers too?
A: The logic is general. Sheriffs, county attorneys, recorders, treasurers, and superintendents of schools are also constitutional or statutory officers with defined duties. Romley v. Daughton (county attorney) and this opinion (assessor) apply the same principle to two of them. Boards cannot use personnel transfer to gut the office.

Q: What if a board and assessor agree to transfer staff?
A: The opinion did not address voluntary cooperation. The principles it identifies are about the board's unilateral authority to act over the assessor's objection.

Q: How would this be enforced?
A: The opinion is persuasive authority. An assessor who believed the board had usurped her duties could seek declaratory and injunctive relief. ADOR's supervisory authority over assessors under § 42-13002 may provide an additional avenue.

Citations and references

Statutes and constitutional provisions:

• Ariz. Const. art. 12, §§ 3, 4
• A.R.S. § 11-251 (board duties)
• A.R.S. §§ 11-541 to 11-543 (assessor duties, oath, liability)
• A.R.S. § 42-13002 (ADOR supervision)
• A.R.S. § 42-13006 (assessor certification)
• A.R.S. § 42-13051 (property identification)
• A.R.S. § 42-11054 (Procedures Manual authority)

Cases:

• Romley v. Daughton, 225 Ariz. 521 (App. 2010)
• Premiere RV & Mini Storage LLC v. Maricopa Cnty., 222 Ariz. 440 (App. 2009)

ADOR materials:

• Assessment Procedures Manual, Part 6

Source

• Landing page: https://www.azag.gov/opinions/i15-013-r15-017
• Original PDF: https://www.azag.gov/sites/default/files/2025-06/I15-013.pdf

Original opinion text

To:

Sheila Polk

Yavapai County Attorney

Questions Presented

Does the Yavapai County Board of Supervisors ("BOS") have the authority to withdraw consent for previously approved cartography and property title personnel positions within the County Assessor's office and assign those positions to a newly formed department that reports to the BOS?

Does the BOS usurp the County Assessor's authority in the following situations?

1. By transferring cartography functions previously performed by the County Assessor to a county department that reports to the BOS?

a. May the County Assessor rely upon cartography services provided by a county department to fulfill her statutory duties or is the Assessor required to perform her own cartography functions or otherwise supervise those functions?

b. Does the assignment of assessor parcel numbers to parcels of property pursuant to the Arizona Department of Revenue ("ADOR") guidelines by a county department, usurp the authority of the County Assessor?

c. Does the assignment of tax area codes to parcels of property by a county department, usurp the authority of the Assessor?

2. By transferring property title functions previously performed by the County Assessor to a county department that reports to the BOS?

a. May the County Assessor rely upon property title functions provided by a county department to fulfill her statutory duties or is the Assessor required to perform her own property title functions or otherwise supervise those functions?

b. May a county department enter affidavit of value information into the County Assessor's database without usurping the County Assessor's statutory duties, when such entry is a verbatim account of the affidavit information?

c. Is there a usurpation of authority when affidavit of value information has been interpreted, adjusted or classified by the county department prior to entry into the County Assessor's database? Is there a usurpation if such data entry is done with the input of the County Assessor?

d. May a county department that reports to the BOS determine title and ownership of real property parcels or process splits and combination of parcels without usurping the Assessor's statutory duties?

3. If a[n] usurpation of authority has been found in numbers 1 or 2 above, does the County Assessor's ultimate ability to review and override any data entered into the Assessor's database by a county department change the analysis?

Summary Answers

The various questions articulated provide for a detailed review of what is, essentially, a singular primary question: Did the BOS act beyond its authority and usurp the County Assessor's authority when the BOS removed certain personnel from the County Assessor's control? The summary answer to that overriding question is yes, the BOS exceeded its authority.

The BOS does not have the authority to withdraw cartography and title personnel from the control of the Yavapai County Assessor ("Assessor") given that the functions of those personnel are necessary for an assessor to perform its statutory duties. Among other duties, an assessor is required to identify, by diligent inquiry, all real property in the county that is subject to taxation, to maintain uniform maps and records with assistance from ADOR, to report detailed property information on the tax roll, to account for all property in a county, and to supply geographical information to various county taxing districts. Cartography and title functions are necessary to an assessor's performance of these and many other statutory duties.

Background

A. County Assessor Enabling Authority

Article 12, Sections 3 and 4 of the Arizona Constitution provide that county assessors are elected officials whose duties and powers are those "as prescribed by law." Arizona Revised Statutes ("A.R.S.") 11-541 similarly provides that county assessors "shall have the powers and perform the duties prescribed by law." Every assessor must hold an assessor's certificate issued or recognized by ADOR, which demonstrates that ADOR recognizes the assessor's competency. A.R.S. § 42-13006. Moreover, a county assessor is "liable for all taxes on taxable property within the county which, through the neglect of the assessor, remains unassessed." A.R.S. § 11‑543. Thus, county assessors must perform, must be competent to perform, and must have the power and resources to perform their constitutional and statutory duties.

B. County Assessor's Duties

County assessors are tasked with "truly and fairly determin[ing] the valuation, without favor or partiality, of all the taxable property in [their] county at its full cash value." A.R.S. § 11-542 (assessor oath of office). Section 42-13051 provides:

A. Not later than December 15 of each year the county assessor shall identify by diligent inquiry and examination all real property in the county that is subject to taxation and that is not otherwise valued by the department as provided by law.

B. The assessor shall:

1. Determine the names of all persons who own, claim, possess or control the property, including properties subject to the government property lease excise tax pursuant to chapter 6, article 5 of this title.

2. Determine the full cash value of all such property as of January 1 of the next year by using the manuals furnished and procedures prescribed by the department.

3. List the property with the determined valuation for use on the tax roll and report to the department of education the determined valuations of properties that are subject to the government property lease excise tax pursuant to chapter 6, article 5 of this title.

C. In identifying property pursuant to this section, the assessor shall use aerial photography, applicable department of revenue records, building permits and other documentary sources and technology.

(Emphases added.)

With respect to their duty to identify property, county assessors must maintain uniform maps and records for their county with assistance from ADOR. A.R.S. § 42-13002(A)(3). ADOR is tasked with "exercis[ing] general supervision over county assessors in administering the property tax laws to ensure that all property is uniformly valued for property tax purposes." A.R.S. § 42-13002(A)(1). An assessor must comply with the guidelines and manuals promulgated by ADOR when assessing property. A.R.S. § 42-11054(A)(1). In ADOR's Assessment Procedures Manual (the "Procedures Manual"), ADOR describes an assessor's duties as follows:

The County Assessor's principle [sic] responsibilities include the location, inventorying and appraisal of all locally assessable property within their jurisdictions. The performance of these important functions requires a complete set of maps. Maps aid in determining the location of property, indicate the size and shape of each parcel, and can spatially reveal geographic relationships that contribute either negatively or positively to appraised values. In addition to the Assessors, many other governmental agencies, the general real estate community and the public rely on accurate maps. Computerized or digital mapping provides an accurate and cost effective method to map tax areas, appraisal maintenance areas and appraisal market areas.

Procedures Manual at 6.1.2. In furtherance of these duties the Procedures Manual tasks assessors as follows:

Assessors are responsible for discovering, listing and valuing all locally assessable properties within their jurisdictions. The discovery of real property (i.e., parcels of land and any improvements on them) is accomplished through:

1. Field Surveys.

2. The processing of Conveying Documents (Affidavits of Value, deeds, etc.).

3. The creation and processing of Plat Maps (a.k.a. cadastral maps).

4. Studying aerial and ground-based Photographs.

5. The processing of Building Permits.

6. The analysis of Ownership Status Maps (obtained from the State Land Department, the Bureau of Land Management, etc.).

Procedures Manual at 6.1.2-6.1.3.

As the Manual further explains:

"[A] well maintained cadastral mapping system (showing the extent and ownership of land) is essential to provide a standard, accurate legal description, which is needed for the accurate location, identification and inventory of property . . . . Property identification systems were designed and developed to produce a legal description, which prevents a specified parcel from being confused with any other parcel."

Procedures Manual at 6.1.3 (emphasis in original).

Such duties and the resulting information enable county assessors to fulfill their statutory obligations to ensure that all property subject to the jurisdiction of the State is listed on the assessment roll and is cross-indexed. See A.R.S. §§ 42-15151 through 15153.

Many other corollary duties of an assessor as set forth throughout Title 42, Arizona Revised Statutes, depend upon or otherwise relate to an assessor's mapping and title duties. Outside of Title 42, a county assessor has many duties that require the correct identification and mapping of property. Moreover, the assessor is a repository of documents and reports filed by other governmental entities relating to property locations for mapping, split, and ownership purposes, documents and reports that an assessor uses to perform its property valuation and assessment obligations. Finally, numerous government bodies and individuals rely on the mapping and title records of county assessors to perform their obligations.

Moreover, ADOR exercises general supervision over the assessors to ensure that all property throughout the State is fairly and uniformly valued. A.R.S. § 42-13002. ADOR has no authority over a county board of supervisors or its departments.

C. County Board of Supervisors

While Arizona statutes require a county board of supervisors to levy and equalize tax assessments (A.R.S. § 11-251(12)-(13)), they do not vest a county board with authority to identify property or to perform the mapping and titling functions necessary to assess property taxes. Arizona statutes presume that county boards rely upon the assessor's records when performing their duties. See, e.g., A.R.S. §§ 40-344 (requiring the corporation commission, cities or towns, and board of supervisors to mail out notices to persons regarding the establishment of an underground conversion service area based on the records of the county assessor); 42-18303 (requiring county board of supervisors to rely on their county assessor's records related to common areas when selling property to a contiguous property owner).

Analysis

County assessors are elected officials responsible for identifying, mapping, and assessing all property in their counties for property tax and other purposes. They are also responsible for determining the ownership of property for tax and other purposes. These duties, as detailed above, derive from the Constitution and statutes. Consequently, it is beyond a county board of supervisors' authority to divest a county assessor of those duties.

Consistent with that premise, the Arizona Court of Appeals has recognized under analogous circumstances the inherent limitations on a county board of supervisors' authority. In Romley v. Daughton, 225 Ariz. 521 (App. 2010), the Maricopa County Board of Supervisors determined that the Maricopa County Attorney had a conflict of interest that prevented him from adequately representing the Board in most civil matters. The Board established a General Litigation Department to represent the County in most new civil litigation matters in place of the County Attorney, based on cases holding that a county board could hire outside counsel where a county attorney refuses to act, is incapable of acting, or is unavailable for some other reason. The Court of Appeals determined that although the County Board could employ outside counsel in situations in which an ethical conflict existed, the County Attorney still had the power and authority to represent the County in civil litigation matters:

[A] county board of supervisors would exceed its authority in effectively divesting the county attorney of his power to represent the county and its agencies without the requisite determination on a case-by-case basis of unavailability of the county attorney or a lack of harmony between the board and the county attorney.

Id.at 526, ¶ 25.

Similarly here, the Yavapai County Assessor must have the ability to identify and map properties and to determine the ownership of properties in order to fulfill her statutory duties relating to the valuation and assessment of property and her statutory obligations to other governmental agencies. The BOS cannot remove cartography and property title personnel from the assessor's office without unlawfully divesting the assessor of mapping and title functions that she is required to perform under state law. Further, given that ADOR has no authority over a county board of supervisors, in contrast with its general supervisory authority over assessors, transferring these functions to a board of supervisors would obstruct ADOR's supervision of the assessment of property in Yavapai County.

A. Does the Yavapai County Board of Supervisors ("BOS") have the authority to withdraw consent for previously approved cartography and property title personnel positions within the County Assessor's office and assign those positions to a newly formed department that reports to the BOS?

No. For the reasons stated above, the BOS cannot preclude the County Assessor from controlling cartography and title departments necessary to the performance of the Assessor's duties. Given that cartography and title functions are necessary to the Assessor's performance of these duties, the Assessor must retain and control those departments.

B. Does the BOS usurp the County Assessor's authority in the following circumstances?

1. By transferring cartography functions previously performed by the County Assessor to a county department that reports to the BOS?

Yes. The BOS could not transfer cartography functions to a county department that is not controlled by the Assessor without impairing the Assessor's ability to perform her statutory duties, which specifically include maintaining uniform maps and records for the County with the assistance of ADOR. Moreover, ADOR's Procedures Manual, promulgated pursuant to A.R.S. § 42-11054, requires county assessors to create and maintain maps and related documents as part of their duties. Part 6, Procedures Manual, Eff. 3/1/11; see also A.R.S. § 42-13002(A)(3)(a) ("The department shall . . . [a]ssist county assessors [i]n maintaining uniform maps and records."). Moreover, as noted above, divesting the County Assessor of these tasks also prevents ADOR from overseeing the Assessors' mapping and related assessment duties.

a. May the County Assessor rely upon cartography services provided by a county department to fulfill its statutory duties or is the Assessor required to perform its own cartography functions or otherwise supervise those functions?

No. As set forth above, mapping properties and performing related cartography functions are duties the Assessor is statutorily obligated to perform in accordance with ADOR's Procedures Manual. The BOS may not divest an assessor of those functions and of the personnel needed to perform those functions.

b. Does the assignment of Assessor parcel numbers to parcels of property pursuant to the Arizona Department of Revenue (the "Department") guidelines by a county department usurp the authority of the County Assessor?

Yes. Property identification is central to the Assessor's duties, and numerous statutes require various entities to rely on the Assessor's parcel number or otherwise address the assessor's issuance of a parcel number. The Assessor plainly has the power to oversee and control the issuance of parcel numbers, including the execution of parcel splits and consolidations, as required by statute and ADOR's Procedures Manual. See, e.g., Premiere RV & Mini Storage LLC v. Maricopa Cnty., 222 Ariz. 440, 447 ¶ 29 (App. 2009) (holding that a split occurs, for tax purposes, when the assessor completes the process of identifying and valuing resulting parcels following sale of a portion of a parcel).

c. Does the assignment of tax area codes to parcels of property by a county department usurp the authority of the Assessor?

Yes. Creating a department not controlled by the Assessor to assign tax area codes to parcels of property would directly impair the Assessor's ability to perform her statutory duties and comply with ADOR's Procedures Manual.

2. By transferring property title functions previously performed by the County Assessor to a county department that reports to the BOS?

Yes. Transferring property title functions to a county department that is not controlled by the Assessor would impair the Assessor's ability to perform her statutorily required duty to identify property and ownership for property tax purposes.

a. May the County Assessor rely upon property title functions provided by a county department to fulfill its statutory duties or is the Assessor required to perform its own property title functions or otherwise supervise those functions?

As set forth above, the BOS cannot divest the Assessor of the property title functions that an assessor is obligated to perform by statute and/or in accordance with ADOR's Procedures Manual. This question is thus moot.

b. May a county department enter affidavit of value information into the County Assessor's database without usurping the County Assessor's statutory duties when such entry is a verbatim account of the affidavit information?

No. As set forth above, statutes and ADOR's guidelines require the Assessor to maintain and update its database. Consequently, the BOS cannot usurp that function through one of its departments.

c. Is there a usurpation of authority when affidavit of value information has been interpreted, adjusted or classified by the county department prior to entry into the County Assessor's database? Is there a[n] usurpation if such data entry is done with the input of the County Assessor?

Yes. The BOS would significantly impair the ability of the Assessor to perform its duties by allowing a county department not controlled by the Assessor to interpret, adjust, or classify affidavit of value data. Divesting the Assessor of those functions would unlawfully usurp the Assessor's authority.

d. May a county department that reports to the BOS determine title and ownership of real property parcels or process splits and combination of parcels without usurping the Assessor's statutory duties?

No. The BOS would impair the Assessor's ability to perform its duties by allowing a county department not controlled by the Assessor to determine title and ownership of real property parcels or process splits or combinations of parcels. The Assessor is responsible for determining the names of all persons who own, claim, possess or control property in the County, and for processing parcel splits and combinations. Divesting the Assessor of those functions would unlawfully usurp the Assessor's authority.

3. If a[n] usurpation of authority has been found in numbers 1 or 2 above, does the County Assessor's ultimate ability to review and override any data entered into the Assessor's database by a county department change the analysis?

No. As explained above, the Assessor can only fulfill her statutory duties by controlling the personnel who perform the functions necessary to those duties as well as the processes by which they perform those functions. The BOS would usurp those functions by relegating the Assessor to a "review and override" role. Moreover, by removing mapping and title personnel from the Assessor's authority, the BOS will have removed the Assessor's ability to review and analyze the data entered into the Assessor's database by BOS personnel.

Conclusion

The BOS would unlawfully usurp the Assessor's statutory authority by eliminating cartography and title personnel positions within the Assessor's Office or by performing the Assessor's cartography and title functions through personnel who report to the BOS.

Mark Brnovich

Attorney General