Building an underground bunker in Wyoming.

Licensing and permits

Wyoming does not issue a statewide general contractor license. Licensing, where it exists, is set by cities and counties, while electrical work is licensed by the state Department of Fire Prevention and Electrical Safety. Wyoming also has no statewide residential building code, so the rules for a bunker depend entirely on the county. The Wyoming land guide covers water permits and taxes. We build to the International Residential Code everywhere, whether or not a county requires it.

Radon

The Wyoming State Geological Survey calls radon the most widespread geologic hazard in the state and has found elevated levels in all 23 counties, with high rates above the action level in Lander, Sheridan, Jackson and Casper. For a space people will sleep in below ground, that settles the question: every Styrkholm bunker in Wyoming gets active radon mitigation, a sealed shell and positive-pressure filtered air, and is tested before use.

Bentonite and landslides

Much of Wyoming's clay is shrink-swell, including bentonite, found mainly in Cretaceous shales and volcanic ash. It expands when wet and shrinks as it dries, which can crack or heave a structure. The state survey has also mapped more than 33,000 landslides. A buried structure is surrounded by soil on every side, so we test for expansive clay before choosing a site and design the drainage, backfill and structure around what we find.

Earthquakes

The Wyoming State Geological Survey reports that parts of Lincoln, Sublette, Fremont, Teton and Park counties have a greater than 50 percent chance of damaging shaking over 100 years, and that faults in western Wyoming could produce earthquakes of magnitude 7.2 to 7.5. The Teton fault alone is 60 to 70 kilometers long. In the western counties, the bunker is engineered for it.

Frost, snow and wildfire

Teton County designs for 34 inches of frost; Casper requires three feet to the top of the footing. Snow loads are local: Casper uses 30 pounds per square foot, while Teton County directs designers to the ASCE hazard tool, which runs much higher in the mountains. Teton County has adopted the 2021 International Wildland-Urban Interface Code, and a resolution would extend it to all unincorporated areas.

Septic

Wyoming's Department of Environmental Quality permits small wastewater systems directly only in Carbon, Niobrara, Platte and Weston counties, and commercial systems in Campbell County. Elsewhere the county or city issues the permit. We confirm which before the site plan is drawn, and plan an ejector pump for any fixtures below the septic line.

How we build in Wyoming

A Wyoming compound trades regulation for responsibility. With few state rules to lean on, we set our own: geotechnical testing for bentonite, radon mitigation on every below-grade space, engineering for western faults and mountain snow, and distance from the Minuteman missile field around Cheyenne. Western Wyoming offers the water and timber; the east offers space.

Escape openings

The International Residential Code, which these states and most of their counties build from, has a Section R310 that requires an emergency escape and rescue opening in basements and in every sleeping room below grade. A bunker is designed around that from the start: a second way out, sized and protected so it can be opened from inside after a storm, a fire or a collapse at the main entry. Some states amend R310, Utah among them, so we confirm the local version for each site.

Questions

This page is general information, current to October 2026. It is not engineering or legal advice. Codes, snow loads and frost depths are set locally and change; we confirm every requirement for a specific Wyoming parcel with the responsible jurisdiction before design.