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Costilla County Assessor

County Assessor Property Search | Colorado Division of Property Taxation

Costilla County GIS Property Search

Thomas Aragon

County Assessor

P.O. Box 344

San Luis, CO 81152

Phone: (719) 937-7670

eFax: (888) 709-5722



Office Hours:

Monday - Thursday: 7:00 a.m. - 5:30 p.m.

No closure for lunch.




About Our Office

This office is directly responsible for discovering, locating, classifying and valuing properties. It is the responsibility of this office to update and maintain accurate property records. These records include improvements and all improvement characteristics, along with pictures of these improvements. Records also include land size, location, maps and transfer history.



Thomas Aragon - Assessor

Ronda Lobato - Deputy Assessor/Chief Appraiser

Pamela Vigil - Office Manager

Steve Valdez - Transfer Clerk

Loryn DeLeon - Field Inspector

Angelica Valdez - Field Inspector 

Benita Martinez - Administrative Assistant


2023-2024 Reappraisal Information

Protest Information

Protest Form

Notice of Valuation Form

Sales Gathering Period Timeline

Residential Sales Book

Reappraisal Reduction Information for 2023 taxes

Time Trend Explained

2023 Vacant Land Sales Book with Time Trend

2023 Agricultural Land Appraisal

Video on Colorado appraisal -

Colorado Map on percentages of increase in each county-



2021-2022 Reappraisal Information

Protest Information

Residential Sales Book

Sales Gathering Periods Explanation

Study Period Graph 2021

Vacant Land Sales Book

Agricultural Land Valuation

Agricultural Land Valuation Summary

Why Adjust for Time or Market Condition Changes

Forbes Wagon Creek Residential Sales

2019-2020 Reappraisal Information

Helpful Information

Mass Appraisal Explained

New Ag Values Per Acre

Residential Sales Reappraisal 2019

Sales Gathering Periods Explanation

Vacant Land Sales Reappraisal 2019

Abstract Brochures

2022 Abstract Brochure

2021 Abstract Brochure

2020 Abstract Brochure

2019 Abstract Brochure

2018 Abstract Brochure

2017 Abstract Brochure

2016 Abstract Brochure

Classification and Valuation of Agricultural Property

Understanding Property Taxes in Colorado

Property Valuation and Taxation for Business and Industry

Rebates, Exemptions, and Deferrals for Senior Citizens, Persons with Disabilities and Active Members of the National Guard or Reserves

Manufactured Homes

Natural Disaster Valuation in Colorado

Property Tax Exemption for Disabled Veterans and Gold Star Spouse in Colorado

Property Tax Exemption for Senior Citizens in Colorado



Address Change Form

Petition for Abatement or Refund of Taxes (One Year Form)

Petition for Abatement or Refund of Taxes (Two Year Form)

Real Property Transfer Declaration (TD-1000)_Revised 1-16-21


Property Tax Exemption Application for Qualifying Disabled Veterans 2023

Disabled Veteran Form Instructions 2023

Disabled Veteran Surviving Spouse Form 2023

Gold Star Spouse  Application and Instructions 2023

Senior Citizen Long Form Application 2023

Senior Citizen Long Form Instructions 2023

Senior Citizen Short Form Application 2023

Senior Citizen Short Form Instructions 2023


Helpful Links

Department of Local Affairs

Colorado Assessors' Association