Building permits, zoning and land rules in Crook County, Wyoming

At a glance

Building permit

Not required anywhere in Crook County; no adopted building code and no inspections performed by the county¹⁸

Zoning

None countywide; the Town of Pine Haven zones within its town limits and planning boundary⁹⁷

Septic permits

Crook County Planning (Growth & Development); $200 Permit to Construct and inspection fee, for systems 2,000 gal/day or less⁵¹⁰

Owner-builder

Yes: with no county building permit to begin with, there's no permit process to be exempt from¹¹¹²

Large Acreage Subdivision minimum lot

35 acres minimum per created parcel (up to 140 acres) outside exempt divisions¹³

Well permit

Required statewide from the State Engineer before drilling; $50 filing fee for domestic or stock use¹⁴

State highway driveway access

Requires a WYDOT district engineer permit for any access onto a state highway¹⁵

Septic soil difficulty

19.9% of county soils are free of severe limits for a conventional drain field — better than most rural counties¹⁶

Who to call

Contact details are copied from each office’s official page and were checked against it on September 23, 2026.

Do you need a building permit in Crook County, Wyoming?

No. Crook County's official Land Use Zoning Building Permit Information states directly that the county does not have land use regulations, zoning regulations, adopted building codes, or building permit requirements for residential, commercial or industrial construction⁸¹⁷. That covers inspections too: the county doesn't perform residential, commercial or industrial building construction inspections, and it doesn't issue certificates of occupancy³⁴. Wyoming law explains why this is possible: counties only get building-code enforcement authority if they apply for and receive delegation from the State Fire Marshal, adopting standards at least as strict as the state's; Crook County hasn't taken on that role, so no permit requirement applies¹⁸. The county still recommends that construction follow Wyoming's state-adopted codes and referenced standards, even without a permit process to enforce them⁸.

Who handles land-use and septic questions in Crook County, and how do you reach them?

Crook County Growth & Development, the county's Planning Department, is the office that confirms there's no zoning, building code or permit requirement, and it's also the office that administers the county's Large Acreage Subdivision rules¹⁹¹³. For septic systems specifically, the same department runs the Small Wastewater Program: applications go to Crook County Planning at the Crook County Courthouse in Sundance²⁰¹⁰. If your parcel is inside the Town of Pine Haven or its planning boundary, zoning and subdivision questions go to the Town of Pine Haven's own Planning Commission instead of the county⁷. Access onto a state highway is a different office entirely: WYDOT's district engineer, not the county, issues that permit¹⁵.

Does Crook County have zoning?

No, not countywide. The county's official summary is unambiguous: Crook County does not have land use regulations or zoning regulations². Wyoming law gives counties general authority to zone unincorporated land, but Crook County has chosen not to exercise it²¹. The one exception is the Town of Pine Haven, whose Planning Commission oversees development, zoning map amendments, and subdivision regulations within town limits and its planning boundary; land inside that boundary follows Pine Haven's rules, not the county's absence of rules⁷. Outside Pine Haven, there's no county-set minimum lot size, setback or building height for an ordinary home — the one dimensional standard that does reach unincorporated land is the Large Acreage Subdivision Regulation, which generally bars creating parcels smaller than 35 acres (up to 140 acres) without a Board-approved variance¹³²². Wyoming's broader Real Estate Subdivisions Act reinforces that large-parcel path: land divided into parcels 35 acres or larger is generally exempt from the state's subdivision-permit process altogether, as long as each parcel gets a recordable 40-foot easement to a public road²³.

How do septic permits work in Crook County?

Any small wastewater (septic) system treating 2,000 gallons per day or less in Crook County needs a Permit to Construct from Crook County Planning before you start building it²⁰¹⁰. The process: submit a completed Crook County Conventional Small Wastewater Application Packet, pay the $200 fee, which covers both the Permit to Construct or As-Built Permit and the required inspection, and wait for approval from the Planning Administrator before construction begins²⁴²⁵. Crook County Planning inspects the system before it's backfilled or covered, so schedule that inspection before you close the trench²⁶. Systems that exceed 2,000 gallons per day, or that carry wastewater that isn't entirely domestic, fall outside county authority and go to the Wyoming DEQ Underground Injection Control Program instead⁶. Soils here are more forgiving than in many rural counties: 19.9% of Crook County's soils are free of severe limitations for a conventional drain field, well above the single-digit rates common elsewhere¹⁶. If you also need a well, Wyoming requires a permit from the State Engineer's office before drilling, with a $50 filing fee for domestic or stock use and a completion report due within 30 days of finishing¹⁴.

Can you live in an RV or tiny home on your land in Crook County?

Crook County's official materials don't establish a specific rule for RV living, temporary camping, tiny homes or manufactured-home occupancy on private land — all of these are open questions in the official sources reviewed for this guide². The absence of county zoning means there's no county-imposed minimum dwelling size, lot coverage limit or occupancy permit standing in your way, but that's different from a confirmed right to occupy any structure you like; no official Crook County source directly addresses the question either way. If your land is inside the Town of Pine Haven or its planning boundary, that town's own zoning and subdivision rules would govern instead of the county's silence⁷. One practical note for manufactured or mobile structures: Wyoming's electrical-safety law lets a property owner do their own electrical installation work on property they own and don't intend to immediately resell, without needing a licensed electrician, though all other code requirements still apply²⁷.

Building a home in Crook County: the steps, in order

First, confirm whether your parcel is inside the Town of Pine Haven or its planning boundary, since that's the one place county rules don't apply and town zoning takes over instead⁷. Second, if your land needs a well, file a U.W. 5 Application for Permit to Appropriate Ground Water with the State Engineer's office and wait for approval before drilling; use a Wyoming-licensed well driller¹⁴. Third, apply for your septic Permit to Construct through Crook County Planning, paying the $200 fee, before starting construction of the system²⁰¹⁰. Fourth, if you're creating a new parcel rather than building on an existing one, confirm it meets the Large Acreage Subdivision Regulation's 35-acre minimum, or check whether it qualifies for an exemption¹³. Fifth, if your driveway will connect to a state highway, apply to the WYDOT district engineer for an access permit; expect roughly four weeks for processing¹⁵. Sixth, build: there's no county building-permit review or inspection to schedule anywhere in Crook County⁸. Seventh, schedule your septic inspection with Crook County Planning before the system is backfilled or covered²⁶.

What to check before you buy land in Crook County

Confirm first whether the parcel falls inside the Town of Pine Haven's town limits or planning boundary, since that's the one place with active zoning in the county⁷. Soils here are relatively favorable for septic: 19.9% of Crook County's land is free of severe limitations for a conventional drain field, meaningfully better than the low single digits common in many rural counties, though a site evaluation is still required before permitting¹⁶. The terrain is moderate — 56.5% of land sits at 15% slope or less and 27.6% is forested — and drought is a real factor here, with 18.6% of years bringing severe drought and only 18.3 inches of precipitation annually, so a reliable water source matters more than in wetter counties^28293031. If you're buying a smaller tract, check whether it was created under the Large Acreage Subdivision Regulation's 35-acre minimum or qualifies for an agricultural exemption¹³. Federal land makes up 14.2% of the county, which can affect road access and neighboring land use in some areas³². Typical property tax runs low here, about 0.5% effectively, with a median bill near $1,522 a year against a typical home value around $433,504³³³⁴³⁵.

Watch-outs

• No official Crook County source addresses RV living, temporary camping, tiny homes, manufactured-home siting or accessory dwellings on private land directly; the county's no-zoning statement does not by itself confirm any of these are allowed².
• No official Crook County floodplain development rule was found in the sources behind this guide; if your parcel is near a mapped flood zone, ask Crook County Planning directly, since Wyoming's floodplain program is administered county-by-county for participating communities³⁶.
• The Town of Pine Haven is a real exception to 'Crook County has no zoning' — land inside its town limits or planning boundary follows Pine Haven's own zoning and subdivision rules, not the county's absence of them⁷.

Sources

1. Land Use Zoning Building Permit Information (2026 county census)
2. Land Use Zoning Building Permit Information, quoted and re-checked
3. Land Use Zoning Building Permit Information, quoted and re-checked
4. Land Use Zoning Building Permit Information, quoted and re-checked
5. Small Wastewater (Septic Systems 2000 gallons or less per day) (2026 county census)
6. Small Wastewater (Septic Systems 2000 gallons or less per day), quoted and re-checked
7. Planning & Zoning Commission - Pine Haven, Wyoming, quoted and re-checked
8. Land Use Zoning Building Permit Information, quoted and re-checked
9. Land Use Zoning Building Permit Information (2026 county census)
10. Small Wastewater (Septic Systems 2000 gallons or less per day), quoted and re-checked
11. Land Use Zoning Building Permit Information (2026 county census)
12. Wyoming law on county zoning and building authority
13. Crook County Large Acreage Subdivision Regulation, quoted and re-checked
14. General Processes, quoted and re-checked
15. WYDOT Access Manual, quoted and re-checked
16. Share of soils without severe limits for a conventional septic drain field (USDA SSURGO): Bolthole Index county data
17. Land Use Zoning Building Permit Information, quoted and re-checked
18. Wyoming Statutes, Title 35, W.S. 35-9-121 (Wyoming statewide rule), quoted and re-checked
19. Crook County Growth & Development (Planning Department) (crookcounty.wy.gov)
20. Crook County Planning, Small Wastewater Program (crookcounty.wy.gov)
21. Wyoming Statutes, Title 18, W.S. 18-5-201 (Wyoming statewide rule), quoted and re-checked
22. Crook County Large Acreage Subdivision Regulation, quoted and re-checked
23. Wyoming Statutes, Title 18 (Wyoming statewide rule), quoted and re-checked
24. Small Wastewater (Septic Systems 2000 gallons or less per day), quoted and re-checked
25. Small Wastewater (Septic Systems 2000 gallons or less per day), quoted and re-checked
26. Small Wastewater (Septic Systems 2000 gallons or less per day), quoted and re-checked
27. W.S. 35-9-123. Electrical installations to be performed by licensed electricians; exceptions, quoted and re-checked
28. Share of land at 15% slope or less: Bolthole Index county data
29. Wooded share of land: Bolthole Index county data
30. Share of years in severe drought: Bolthole Index county data
31. Annual precipitation: Bolthole Index county data
32. Federal land share: Bolthole Index county data
33. Effective property tax rate: Bolthole Index county data
34. Median property tax bill: Bolthole Index county data
35. Typical home value (Zillow): Bolthole Index county data
36. 2027-2028 Biennium Unit Narrative, Wyoming Office of Homeland Security (Wyoming statewide rule), quoted and re-checked

Written September 23, 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.