Keystone, South Dakota.
Typical home $620,968 (+0.6% in a year). Rapid City, SD metro.
to buy the typical home at today's mortgage rate — +$1,926 (+145%) since Jan 2020.
- 1 year
- Up $3,521 +1%
- $617,446$620,968 since Sep 2025
- 5 years
- Up $140,992 +29%
- $479,976$620,968 since Sep 2021
Monthly payment to buy the typical home
Home value × that month's 30-year mortgage rate, 20% down, principal and interest. This is the line households feel: prices and rates compound each other.
- Keystone$3,259
- South Dakota$1,668
- United States$1,922
At the last five years' pace, a typical home here doubles in price every 13 years.
Typical home values in Keystone, SD rose 0.6% over the past year — slower than the nation's +1.2%.
Living in Keystone, Custer County, South Dakota
Keystone is a town of 240 people in Custer County. Half its households earn more than $64,702 a year and half less, against $84,112 across Custer County; 7% of its people live below the poverty line. Unemployment in Custer County was 2.2% in August 2026, and the county had 0.5% more jobs in 2025 than the year before. The most people in Custer County work in schools and health care, then professional services.
Written by AI Claude Sonnet 5.5 wrote this on 23 October 2026 from the figures here, a list of nearby places and what it knows. It can be wrong or out of date.
What it’s like
The place. Keystone is a very small town in the Black Hills, with a population smaller than most places of its kind. Household incomes in town run below the county's, while typical home values are high. Winters are cold and snowy, with February the coldest month, and summers are mild, with July the warmest. Most adults do not hold a four-year degree.
Work. Residents work mainly in schools, hospitals and social care, in professional and business services, and in farming, forestry and mining, with many also employed in restaurants, hotels and entertainment. Across Custer County, the largest workplaces include the Custer School District, Monument Health Custer Hospital and the Forest Service. Unemployment across the county is low and little changed from a year earlier, and few residents work from home.
Things to do. The Lincoln Borglum Museum and Horse Thief Lake are in or beside town. A short drive away are Sylvan Lake, a reservoir, and Rushmore Cave, a tourist attraction. Wind Cave National Park, a national park, is a longer drive away.
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- 14%of adults have a degree
- 7%below the poverty line
- 4%work from home
What people in Custer County work in
Employed residents by industry, from the Census survey. Custer County had 2,690 jobs in 2025, 0.5% more than the year before (Bureau of Labor Statistics).
Weather through the year
Coldest in February, with highs near 36° and lows near 18°; warmest in July, with highs near 79° and lows near 59°. About 59 inches of snow and 24 inches of rain and melted snow a year.
Average daily high and low, 1991–2020, at the Mount Rushmore Nmem weather station, 2 miles away (NOAA).
Largest workplaces in Custer County
- Custer School District 16-1School district170FTE
- Monument Health Custer HospitalCritical access hospital134FTE
- Forest ServiceFederal government · Department of Agriculture109
- Monument HealthCommunity health centers and clinics, outpatient33
- Black Hills Electric CooperativeDistribution of electric power28
- M.G. Oil CompanyConvenience food stores28
- National Park ServiceFederal government · Department of the Interior24
Staff on average in 2025, as each workplace reported it to OSHA with its injury records: 4 workplaces with 20 or more staff, 230 people in all across the county; Keystone has none of its own. School districts come from the Common Core of Data (NCES, 2023–24), hospitals from their Medicare cost reports (CMS, 2023) and federal offices from OPM's federal workforce data (2026); FTE marks full-time equivalent staff. Not listed: many offices and banks, which need not report to OSHA; military bases, whose staff OPM withholds; and, in about half the states, city and county governments.
Natural hazards
- WildfireRelatively high
- HailRelatively high
- Winter weatherRelatively high
- Inland floodingRelatively high
- LightningRelatively high
- LandslidesRelatively moderate
FEMA’s National Risk Index (December 2025) rates the risk each natural hazard poses to the people, buildings and farms in Keystone’s census tracts, against the rest of the country; all of them together, relatively moderate. It is meant for planning, not a substitute for a local risk assessment or a flood map: FEMA’s index.
From the U.S. Census Bureau’s 2020 census and its American Community Survey (2020–2024 five-year estimates), and the Bureau of Labor Statistics. A survey, so each figure has a margin of error, and figures it is not sure of are left out. More on Custer County and the Rapid City, SD metro.
Keystone home values
Zillow measures a city over its municipal boundary. Against the state and national figures, mid-tier homes, smoothed and seasonally adjusted.
- Keystone$620,968
- South Dakota$317,874
- United States$366,157
When this market ran hot
Each cell is that month's year-on-year home-value growth. Read left to right, top row is the latest year — the 2021–22 band is the boom.
Market heat, inside the city limits
Homes for sale
Active for-sale inventory. More supply hands power to buyers.
- Keystone13
Zip codes with a Keystone address
A different geography, not a breakdown. The figure above covers the municipality; these zips cover everywhere the Post Office calls Keystone — often including townships beyond the city limits. Both come straight from Zillow, and they are not expected to average out.