When was Crook County founded?

Crook County was founded in 1875, formed from Albany County and Laramie County, and named after George Crook.

What is the county seat of Crook County?

The county seat of Crook County is Sundance.

Is there an online parcel map for Crook County?

Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.

Has Crook County's boundary or name changed?

Crook County was created in 1875 from Albany County and Laramie County. Since then the Atlas of Historical County Boundaries records 6 later changes, chiefly involving Campbell County, Weston County and Albany County.

Is my lot in a flood zone?

We do not have flood maps for Crook County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Crook County, Wyoming: parcels, history and offices

Where it is

Crook on the map of Wyoming

Wyoming has 23 counties and county equivalents, each with its own records office. Shapes with a page are links.

Counties of Wyoming · Crook highlighted

History

Formed in 1875 from Albany County and Laramie County

An old deed may name a county that no longer exists, or a boundary that has since moved.

Crook County was created by Wyoming Territory on December 8, 1875, from parts of Albany and Laramie counties, though it remained attached to those counties for administrative purposes until it was fully organized on January 22, 1885. The county was named after George Crook. In 1890, Weston County was created from Crook, and in 1911, Campbell County was created from Crook, with boundaries adjusted accordingly.

Boundary changes from the Newberry Library, Atlas of Historical County Boundaries.

1875
Crook County created Crook created by Wyoming Territory from Albany and Laramie; Crook not fully organized, attached to Albany and Laramie "for judicial and all other purposes."
from Albany from Laramie
8 December 1875 · Whitehead, 198-201; "Crook County v. Sheridan County," in Wyoming Rpts., 17:424-467
1885
Changed Crook fully organized, detached from Albany and Laramie.
Albany Laramie
22 January 1885 · Trenholm, 1:331
1890
Lost territory Crook lost to creation of Weston. Weston not fully organized, attached to Crook for administrative and judicial purposes.
to Weston
12 March 1890 · Wyo. Terr. Laws 1890, 11th leg., ch. 47/pp. 79-80
1890
Changed Weston fully organized, detached from Crook.
Weston
16 May 1890 · Trenholm, 1:331
1890
Became part of Wyoming Crook became a county in the state of Wyoming. 10 July 1890 · Wyoming Constitution 1889, art. 12 in Swindler, 10:493; U.S. Stat., vol. 26, ch. 664[1890]/pp. 222-226; Van Zandt, 145
1911
Lost territory Crook lost to creation of Campbell. Campbell not fully organized, part attached to Crook "for judicial, revenue and election purposes." Crook boundaries redefined to run on federal land survey lines. Technically, Campbell had been created on 13 February 1911, but the several boundary laws of February 1911 were not passed in the intended sequence and mapping them in strict chronological order is not practical. By treating the law of 21 February as the basic structure that the other laws modify, the mapping reflects the intent of the legislature.
to Campbell
21 February 1911 · Wyo. Laws 1911, 11th leg., ch. 14/pp. 15-16 and ch. 77, secs. 5, 7, 11/pp. 106-108, 111
1911
Changed Campbell fully organized, detached from Crook.
Campbell
23 May 1911 · Trenholm, 2:518

Land and parcels

What the maps cover in Crook

Who publishes each layer, how good it is, and when we last checked.

Parcels Missing

No public parcel map found for Crook County yet. Lot lines and owners of record are kept by the county (crookcounty.wy.gov).
Address points Missing

No public address points layer found for Crook County yet.
Buildings Reference

Roof outlines traced from aerial imagery from FEMA Response Geospatial Office with Oak Ridge National Laboratory (ORNL). Good for seeing what is on a lot; not accurate enough to set a fence from.
checked 18 October 2026

Official: from the office that keeps the record
Good enough: a reliable statewide or national copy
Fallback: a guide only; check the official record
Missing: nothing public found yet

People and land

Crook by the Census

Population

7,181 2020 Census count

Housing units

3,672 2020 Census count

Land area

2,854 square miles

Water area

11 square miles

People per sq mi

3 population ÷ land area

Source: US Census Bureau, 2020 Census; US Census Bureau, 2020 Gazetteer Files. Not endorsed or certified by the Census Bureau.

Rules and offices

Crook County's official site

We have found the county's site but not its offices yet; start there.

County government

County government
The official website of Crook County.
crookcounty.wy.gov

See your own lot on these maps

Open Crook County on Parcel Chart's free map and click your parcel. Save it with a free account; the full record of your place (site map, projects, documents) is Pro, in early access.

Open the free map no sign-in Pro early access

Questions

Common questions about Crook County

When was Crook County founded?: Crook County was founded in 1875, formed from Albany County and Laramie County, and named after George Crook.
What is the county seat of Crook County?: The county seat of Crook County is Sundance.
Is there an online parcel map for Crook County?: Not that we have found yet. Lot lines and owners of record are kept by the county assessor's office. When a public parcel map appears, it shows here.
Has Crook County's boundary or name changed?: Crook County was created in 1875 from Albany County and Laramie County. Since then the Atlas of Historical County Boundaries records 6 later changes, chiefly involving Campbell County, Weston County and Albany County.
Is my lot in a flood zone?: We do not have flood maps for Crook County yet. Look up the address on FEMA's Flood Map Service Center, which shows the effective flood map for any lot.

Nearby

Crook CountyWyoming