Can you live off-grid in Lewis and Clark County, Montana?
73
of 100
Significant challenges
Possible, but water will be hard. Only about 19 inches of rain falls a year, so you will rely on a well (near 80 feet here) or hauled water. The growing season is only about 76 frost-free days, so plan on cold-hardy crops and a greenhouse.
What the land says
Rain
Too dry to live on rain. Plan on a well, and on irrigating anything you grow.
About 19 inches a year (PRISM, 1991 to 2020 average)
Wells
Shallow wells, so drilling should be one of the cheaper costs.
The typical well here is about 80 feet deep; a well typically runs $5,000 to $11,000
Growing season
Very short. A greenhouse makes the difference.
About 76 frost-free days, USDA zone 4b; last frost about June 20, first about September 2
Sun
Good sun. Size the array and battery bank for winter.
About 4.7 hours of full sun a day, averaged over the year
Flood
Flood zones run along creeks and rivers here. Look up the parcel on FEMA's flood map.
FEMA maps flood zones within a quarter mile in parts of the county
Wildfire
Low wildfire risk.
U.S. Forest Service wildfire hazard map: Low to Moderate here
Storms
Hurricanes and strong tornadoes are rare here.
NOAA: no hurricane-strength storm within 50 miles since 1975; no strong (EF2 or stronger) tornado within 25 miles since 1990
Terrain
Rolling ground. Look for a flat house site.
Slopes average about 9%, about 4,530 feet above sea level
Soil
Expect a costlier septic system, because the soil stays wet for long stretches. The county's soil test decides.
Loam, poorly drained (USDA soil survey). A mound, sand filter, or treatment unit typically runs $10,000 to $20,000
Road
Paved roads are close by.
Nearest paved road usually within about 1 mile (OpenStreetMap)
Check a Montana parcel, or plan the one you own
Get a free 0-100 off-grid score.
A step-by-step build plan, sizing your solar, water, garden, septic, heat, and buildings.
Is it legal here?
Zoning
Rural land here is often unzoned. Confirm with the county before you build.
Building code
Montana's state building code does not apply to a house unless the city, town, or county has adopted it, so where none has, the state issues no building permit for a home. The state energy code still applies to new homes, through the builder's self-certification.
Rainwater
Collecting it is allowed.
Composting toilets
Allowed.
Water rights
Water belongs to whoever claimed it first. A new well or pond may need a state permit, and a creek may already be claimed.
Drilled to about 80 feet, with pump and pressure tank
Septic
$10,000 to $20,000
Mound, sand filter, or treatment unit
Solar and batteries
$18,000 to $34,000
Sized for a modest household
Road or driveway
$3,000 to $9,000
From the nearest road to a house site
Clearing
$1,000 to $4,000
A house site, solar, and garden
Total
$37,000 to $78,000
Before the house
Before you make an offer on land here
Soil test
Get a soil test before you count on septic.
The soil stays wet, which can rule out a standard system.
Flood map
Look up the parcel on FEMA's flood map.
Flood zones run along creeks and rivers here. Building in one means flood insurance and extra permits.
Zoning
Confirm with the county whether the parcel is zoned.
Rural land in Montana is often unzoned.
Nearby counties
75,011 people live in Lewis and Clark County, about 21.7 per square mile. It ranks tied for 27th of the 56 Montana counties we scored, and Montana ranks 42nd of 50 states.