Longmont Rockhounding Club

Adams County — 303-659-2120
broomfield.org

Alamosa County — 719-589-6365
alamosacounty.org

Arapahoe County — 303-795-4400
netronline.com

Archuleta County — 970-264-8310
e-caa.com

Baca County — 719-523-4332
bacacountyco.gov

Bent County — 719-456-2010
e-caa.com

Boulder County — 303-441-3530
bouldercounty.gov

Broomfield County (City & County of Broomfield) — 303-464-5819
broomfield.org

Chaffee County — 719-539-4016
chaffeecounty.org

Cheyenne County — (719) 767-5664
cheyenne.co.us

Clear Creek County — 303-679-2322
clearcreekcounty.us

Conejos County — 719-376-5585
e-caa.com

Costilla County — (719) 937-7670
costillacounty.gov

Crowley County — (719) 267-5229
qpublic.net

Custer County — 719-783-2218
e-caa.com

Delta County — 970-874-2120
e-caa.com

Dolores County — (970) 677-2385
netronline.com

Douglas County — 303-660-7450
e-caa.com

Eagle County — (970) 328-8640
eaglecounty.us

Elbert County — 303-621-3101
e-caa.com

Garfield County — 970-945-9134
garfieldcountyco.gov

Gilpin County — (303) 582-5451
opengov.com

Grand County — 970-725-3347
grand.co.us

Gunnison County — 970-641-1085
gunnisoncounty.org

Hinsdale County — 970-944-2225
e-caa.com

Huerfano County — 719-738-1191
e-caa.com

Jackson County — 970-723-4751
netronline.com

Jefferson County — 303-271-6511
jeffco.us

Kiowa County — 719-438-5521
kiowacounty-colorado.com

Kit Carson County — 719-346-8946
tylerhost.net

Larimer County — (970) 498-7050
larimer.gov

Las Animas County — (719) 846-2295
courthousedirect.com

Lincoln County — (719) 743-2049
e-caa.com

Logan County — (970) 522-0888
netronline.com

Mesa County — 970-244-1610
mesacounty.us

Mineral County — (719) 658-2331
mineralcountycolorado.com

Moffat County — (970) 824-9102
netronline.com

Montezuma County — (970) 565-3428
montezumacounty.gov

Morgan County — (not retrieved/verified yet)
Otero County — (not retrieved/verified yet).

Morgan County — 970-542-3512
tylerhost.net

Otero County — 719-383-3010
courthousedirect.com

Ouray County — 970-325-4371
e-caa.com

Park County — (not retrieved/verified yet)
Phillips County — 970-854-3151

e-caa.com
Pitkin County — 970-920-5160

pitkincounty.com
Prowers County — 719-336-8000

prowersco.gov
Pueblo County — 719-583-6597

pueblo.org
Rio Blanco County — 970-878-9410

rbc.us
Rio Grande County — (not retrieved/verified yet)

Rio Grande County — (719) 657-3326
tylerhost.net

Routt County — (970) 870-5544
routt.co.us

Saguache County — (719) 655-2521
tylerhost.net

San Juan County — (970) 387-5632
e-caa.com

San Miguel County — (970) 728-3174
sanmiguelcountyco.gov

Sedgwick County — (970) 474-2531
cichosting.com

Summit County — (970) 453-3480
summitcountyco.gov

Teller County — 719-689-2941
tellercounty.gov

Washington County Assessor (Colorado) — (970) 345-6662
cichosting.com

Weld County — (970) 400-3650

Yuma County — (970) 332-5032
yumacounty.net

A county assessor’s office can help with the property and tax-record side of a mining claim, but it usually cannot determine whether a federal mining claim is legally valid.

It may help you find:

The owner of patented mining-claim land or other private property.
Parcel maps, legal descriptions, and assessor parcel numbers.
Tax records and recorded property transfers.
Easements, rights-of-way, and sometimes surface/mineral ownership information.
Whether a quarry or mine is treated as private property for assessment purposes.
Ask the assessor for records using the county name, parcel number, legal description, or mining-claim name. If the parcel is not in the regular tax system, that may indicate—but does not prove—that it is federal land or an unpatented claim.

For an unpatented federal mining claim, the assessor is usually not the primary source.