Land Planning

Big Horn County

What is a Subdivision?

A subdivision is the creation or division of a lot, tract, parcel or other unit of land for the immediate or future purpose of sale, building development or redevelopment, for residential, recreational, industrial, commercial or public uses. The process for subdividing depends on the number of lots being created, the size of the lots being created and the type of subdivision. We encourage landowners to become familiar with the Subdivision Regulations prior to submitting an application for a subdivision.

The Big Horn County Subdivision Regulations were modeled directly from the Wyoming State Statutes, Title 18, Chapter 5, Article 3 and customized to meet the specific needs of our county. They were amended on January 18, 2022. The amendments consist of clarifications of Wyoming Statutes, clarification of Big Horn County Road and Address Management Palicy, clarification of development agreements, clarification of water supply and water rights, additional definitions, addition of an Application for Exemption for an Affidavit of Exemption, additional plat requirements, amended fees, various grammatical errors.

Types of Subdivisions

Exempt Subdivisions

Important Update:

In 2019, The State of Wyoming Legislature passed House Bill 196. This bill changed the requirements for Subdivisions using the family exemption portion of Wyoming State Statue 18-5-303. The 5 and 1 year requirements have changed. Under the revised 18-5-303 (a) (i) (C) adopted on 02/27/2019, any Subdivsion of land using the family exemption must now be titled in the name of the grantor for a period of not less than 10 years prior of the division of land and the creation of a new parcel. The Immediate family member gaining title must now remain the titled owner for a period of not less than 5 years, unless one of the conditions set in  18-5-303 (a) (i) (C) are met.

Our policy is, any Subdivision using the Family exemption filed with the County Clerk on or before 02/26/2019 will use the 5 and 1 year requirements, and filings on or after 02/27/2019 will use the 5 and 10 year requirements. If you have any questions regarding this change please contact the Big Horn County Land Planner.

Use the following link to see the bill: Wyoming State Legislature 2019 House Bill 196  (will open in new window with state website)

A land division that is not required to go through the formal subdivision process, however, an exempt subdivision requires an Affidavit of Exemption to be filed with the Surveyor's Final Plat. Please contact the Land Planning Department for the Application for Exempt Land Division.

Click on the image below to see a graphic that shows some examples of exempt subdivisions:


Note: Not all exemptions are cut and dry; special conditions apply in most cases.  All exemptions and conditions for exemptions are explained in Chapter III, Section 3 of the Big Horn County Subdivision Regulations.

Simple Subdivision

A division of one unit of land into one or up to 5 lots, each smaller than 35 acres. Parcels greater than or equal to 35 acres that are created as part of land division are exempt from the subdivision process.

Major Subdivision

A division of one unit of land into three or more lots, each smaller than 35 acres. A major subdivision includes any subdivision that does not qualify as a simple subdivision.

See the graphic below that shows various types of subdivisions by lot number/size:

LP Examples subdivisions

Process Checklists

We have developed a few checklists to help our customers visualize and keep track of all the moving pieces throughout the process.

Simple Subdivision Process Checklist


To start the process on a new simple subdivision, complete and submit a Simple Subdivision Application to the Land Planning Department. 

To modify any part of an existing subdivision, complete and submit a Subdivision Amendment Application to the Land Planning Department.

To start the process on a new major subdivision, please consult with the Land Planner directly.