Unincorporated Crook County, Wyoming does not require county building permits and has no countywide zoning ordinance or adopted building code1. Crook County Planning still requires approval before septic construction, and large-acreage subdivisions have county permit, access and setback rules2,3.
Do you need a building permit in Crook County, Wyoming?
Unincorporated Crook County does not require county building permits for residential, commercial or industrial construction.
Unincorporated Crook County does not require county building permits for residential, commercial or industrial construction1. Crook County also has no adopted building code, performs no residential, commercial or industrial building-construction inspections, and issues no certificates of occupancy1. The county nevertheless recommends following the construction codes and referenced standards adopted by Wyoming1. An owner-builder may build without seeking an exemption from a county building-permit process because no county building permit is required1. Wyoming separately exempts owner-installed electrical work from electrician licensing when the installer owns or leases the property and the property is not for immediate resale, but the work must still meet other electrical-safety requirements and the exemption does not extend to a subcontractor6. Inside Sundance and Pine Haven, the towns issue their own building permits9,10. Countywide small-wastewater approval remains with Crook County Planning2.
Who handles building-permit and septic questions in Crook County?
Crook County performs no county building-construction inspections and requires no county building permits.
Crook County performs no county building-construction inspections and requires no county building permits1. Crook County Growth & Development handles Large Acreage Subdivision review and small-wastewater applications; its office phone is (307) 283-45482,3,11. Submit the Crook County Conventional Small Wastewater Application Packet to Crook County Planning at the courthouse in Sundance before septic construction2. Sundance and Pine Haven issue town building permits, while county small-wastewater approval and State Engineer well approval remain separate requirements2,7,9,10.
Does Crook County have zoning?
Unincorporated Crook County has no countywide zoning ordinance or county zoning districts.
Unincorporated Crook County has no countywide zoning ordinance or county zoning districts1,12. County zoning sets no lot-coverage or building-height limit, and no zoning-based minimum dwelling size applies there1. Sundance and Pine Haven administer their own zoning; Pine Haven also oversees development within its planning boundary4,5,13. Crook County Planning remains the countywide small-wastewater authority2. Lack of zoning does not remove subdivision rules: the Large Acreage Subdivision Regulation generally covers divisions creating 35- to 140-acre parcels and requires a subdivision permit before plat recording or construction unless exempt3. Covered subdivisions have a 35-acre minimum lot size unless the Board approves a beneficial variance; smaller parcels fall under other county subdivision regulations3. Structures in covered subdivisions require at least 20 feet from any property line, subject to the applicable variance process3.
How do septic permits work in Crook County?
Crook County Planning administers small wastewater systems with flows of 2,000 gallons per day or less.
Crook County Planning administers small wastewater systems with flows of 2,000 gallons per day or less2. Before construction, submit the county application and obtain a Permit to Construct2. Submit the $200 Permit to Construct or As-Built Permit and inspection fee with the completed application2. Crook County Planning must inspect the system before it is backfilled or covered2. A system over 2,000 gallons per day, or one carrying waste that is not entirely domestic, goes to the Wyoming DEQ Underground Injection Control Program instead2. Only 19.9% of Crook County soils are rated “not limited” for a conventional septic drain field; the rating calls for site evaluation and may mean an engineered system, rather than making septic impossible14. Holding tanks are not a permanent answer for a year-round residence; the county limits them to temporary, seasonal or intermittent use, or temporary correction of a failed system, when severe site restrictions prevent conventional septic and no sewer or alternative system is available15.
Can you live in an RV or tiny home on your land in Crook County?
Unincorporated Crook County has no county land-use rule restricting long-term RV occupancy or temporary camping on private land.
Unincorporated Crook County has no county land-use rule restricting long-term RV occupancy or temporary camping on private land1. The county likewise has no land-use rule restricting occupancy of a tiny home, manufactured home or accessory dwelling in an unincorporated area1. These occupancy answers concern county land-use authority; separate state requirements can still apply1. A qualifying septic system needs a county Permit to Construct before installation2. A holding tank cannot serve as permanent sanitation for a year-round residence and requires its own county permit and inspection when the limited-use conditions are met15. Pine Haven applies separate zoning and subdivision regulations within its town limits and planning boundary5,13.
Building a home in Crook County: the steps, in order
Confirm whether the parcel is unincorporated or inside a municipality; Pine Haven applies zoning and subdivision rules within its town limits and planning boundary.
- Confirm whether the parcel is unincorporated or inside a municipality; Pine Haven applies zoning and subdivision rules within its town limits and planning boundary13.
- If the project creates a parcel, resolve Crook County's subdivision-permit process before recording or construction3,16.
- For a covered large-acreage subdivision, plan for the 20-foot property-line setback and obtain the required county-road or highway access permit; public-road approaches must meet the subdivision access standards3.
- Obtain State Engineer approval before drilling a well, and use Wyoming-licensed drilling and pump contractors7.
- Submit the septic application and obtain Crook County Planning's Permit to Construct before installing a qualifying small wastewater system2.
- Build without a Crook County building permit or county building inspection, while following applicable state requirements1.
- Arrange the county septic inspection before backfilling or covering the system17.
What to check before you buy land in Crook County
Before buying a proposed division in unincorporated Crook County, ask Crook County Planning which subdivision permit or transfer exemption applies.
Before buying a proposed division in unincorporated Crook County, ask Crook County Planning which subdivision permit or transfer exemption applies3,18. The large-acreage transfer affidavit includes an exemption allowing no more than 10 parcels from an original parcel, with every new or remaining parcel at least 35 acres; some exemptions require County Commissioner approval18. Access and utility easements must be at least 40 feet wide to a public road unless specifically waived in a binding, recordable document18. Do not assume acreage alone establishes an exemption18. A groundwater well requires State Engineer approval before drilling; the domestic or stock filing fee is $50, and the completion statement is due within 30 days after completion, including pump installation, when the well is ready for use7. Crook County averages 18.3 inches of annual precipitation, and severe drought occurred in 18.6% of years measured14. We could not confirm a county floodplain-development permit rule; ask Crook County Planning about the parcel before building11.
Watch-outs
- Inside Pine Haven, individual septic applications accompany the town building-permit application for lots of at least 1 acre when town sewer is unavailable; the ordinance requests a Permit to Construct and a DEQ-approved plan, so ask the town and Crook County Planning how to coordinate approvals2,10.
- We could not confirm whether Crook County has a floodplain-development permit; ask Crook County Planning before building in a mapped floodplain because participating Wyoming communities require permits under their local ordinances19.
- County building-permit and zoning answers apply to unincorporated land; Sundance and Pine Haven issue town building permits and administer town zoning4,5,9,10.
- Crook County does not permit a permanent holding tank at a year-round residence; limited holding-tank use requires a county permit, inspection and compliant design15.
Sources
19 official pages, each quoted and re-checked · written October 12, 2026
- Land Use Zoning Building Permit Information
- Small Wastewater (Septic Systems 2000 gallons or less per day)
- Crook County Large Acreage Subdivision Regulation
- Town of Sundance: Sundance Code of Ordinances, Appendix C, Section 504. Bulk Regulations (Crook County)
- Town of Pine Haven: Sec. 30-70. Single-family residential district (R-1) (Crook County)
- W.S. 35-9-123. Electrical installations to be performed by licensed electricians; exceptions
- seo.wyo.gov
- Crook County Conventional Small Wastewater Application Packet
- Town of Sundance: Sundance Code of Ordinances, Section 8-23. Permit required (Crook County)
- Town of Pine Haven: Sec. 8-61. Building permits (Crook County)
- Crook County Growth & Development (Planning Department) (crookcounty.wy.gov)
- County Zoning, Licensing and Permitting
- Planning & Zoning Commission
- Share of soils USDA rates "not limited" for a conventional septic drain field (SSURGO). A strict rating: the median county is about 6% and a tenth of counties are 0%, so a low figure means most lots need a site evaluation or an engineered system, not that septic is impossible. Cite it only with that caveat: Bolthole Index county data
- Crook County Holding Tank Application
- Minor Subdivision Application Checklist
- Crook County Conventional Small Wastewater Application Packet
- Exemption Affidavit Concerning Sale or Transfer of 35 to 140 Acres
- 2027-2028 Biennium Unit Narrative, Wyoming Office of Homeland Security (Wyoming statewide rule)
Written October 12, 2026 from the rules quoted below, each taken from an official source and re-checked by an independent reviewer. This is research, not legal advice: rules change, so confirm with the office before you buy or build.
Off-grid gear
Going off-grid in Crook County means bringing your own water and power. The kit we’d start with:
- Water Crystal Quest Filter any source — well, rain, or creek — to drinking-clean.
- Power Bluetti Solar generators and home battery backup for living off the grid.
- Septic Soil percolation test kit Run your own perc test before paying an engineer — the first thing a septic office asks about.
- Water Well water test kit Bacteria, nitrates, hardness — know what the well on a parcel is really pumping.
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