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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.



In an effort to keep our staff safe and reduce the risk of spreading germs, the Costilla County Assessor's Physical Office is closed to the public until further notice.

Our team is working remotely and is available to answer your questions via telephone.

We are able to respond to you and assist you with any questions you may have if you call or email us, just as if we were in the office.

Please call: (719)-937-7670

Please email:

Thomas Aragon,

Costilla County Assessor


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


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

2020 Abstract Brochure

2019 Abstract Brochure

2018 Abstract Brochure

2017 Abstract Brochure

2016 Abstract Brochure

Classification and Valuation of Agricultural Property 2021

Understanding Property Taxes in Colorado 2021

Property Valuation and Taxation for Business and Industry 2021

Rebates, Exemptions, and Deferrals for Senior Citizens, Persons with Disabilities and Active Members of the National Guard or Reserves 2021

Manufactured Homes 2021

Destroyed by Natural Causes 2021



Address Change Form

Senior Citizen Long Form Application 2021

Senior Citizen Long Form Instructions 2021

Senior Citizen Short Form Application 2021

Senior Citizen Short Form Instructions 2021

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

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

Property Tax Exemption for Disabled Veterans 2021

Property Tax Exemption for Senior Citizens 2021

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


Helpful Links

Department of Local Affairs

Colorado Assessors' Association