Short-term kit
RA100 short-term liquid scintillation radon test kit
- Lab fee extra
Method: Liquid scintillation
In home: 48 to 96 hours
Locations and reports
Radon Levels in Harper County, Oklahoma
EPA puts Harper County in Zone 3, its lowest radon zone. Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Nearest county
8.9%
Oklahoma County, 152 miles
- Oklahoma
- 8.9%
- Oklahoma
- 12.6%
Share at 4+ pCi/L, 135 tests, 2006 to 2015
Ground above low
8.9%
6.3 pts below Oklahoma
- Harper
- 8.9%
- Oklahoma
- 15.2%
Share of land USGS rates moderate or high potential
Tests reported
0
None published
A home here needs its own test
EPA radon zone
Zone 3
Lower potential
- 1
- 2
- Zone 3
1 highest, 3 lowest
EPA predicts under 2 pCi/L indoors
Read a result for Harper County
Starts at EPA's action level
EPA’s own thresholds; the figures are the area’s, never this home’s.
EPA’s reading of 4.0 pCi/L
At or above 4 pCi/L
- Under 20 to 1.9 pCi/L
- 2 to 4consider a fix
- 4 and aboveEPA says fix it
This result is at or above 4 pCi/L. EPA recommends fixing a home when the radon level is 4 pCi/L or higher.
The data
Harper County, At a glance
Harper County at a glance
Predicted: EPA radon zone
EPA Zone 3: lower predicted potential
USGS geologic potential: Low across 91% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
No CDC test figures here
CDC has published no radon test figures for Harper County. Oklahoma County, 152 miles away, is the nearest county with a figure over the 2006 to 2015 laboratory totals.
Harper County, Compared
Harper County radon figures, compared
Calculated by Radon411Harper County has no radon test figure of its own from CDC, whose counts over the 2006 to 2015 laboratory totals name 53 other Oklahoma counties and leave it out. Pooled across 53 Oklahoma counties, 12.6% of reported tests reached that level; across every county in the country with a figure, 36.3%.
The nearest counties with a figure are Oklahoma County (152 miles away) at 8.9%, Washington County (209 miles away) at 11.3% and Tulsa County (213 miles away) at 6.0%. Statewide for the same period, Delaware County reported the highest share (44.7%) and Tulsa County the lowest (6.0%).
EPA's 1993 map puts Harper County in Zone 3, its lowest label: a predicted county average under 2 pCi/L. USGS geology rates 91% of the county's land low radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Harper County, Geology
The ground under Harper County
PredictedMost of the ground under Harper County is one class on USGS's geologic map: 91.1% of its land is low radon potential, with 8.9% moderate. The map puts 91.1% of Harper County in the area it calls Central Oklahoma Plains and Hills and 6.9% in Cimmaron River Valley, with one smaller area beside them. USGS gives the first a radon index of 7, in the low band (5 to 8), and the second 10, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Central Oklahoma Plains and Hills | Nonmarine Permian and Tertiary rocks, including shale, sandstone, and conglomerate in the western part, and Mississippian and Pennsylvanian rocks in the eastern part. | Low | 7 | 91.1% |
| Cimmaron River Valley | Tertiary and Quaternary sandstone, siltstone, shale, and alluvium overlain by eolian sand and loess. | Moderate | 10 | 6.9% |
| High Plains | Tertiary sandstone, siltstone, shale. | Moderate | 9 | 1.7% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Harper County beside the ground around it
Across Oklahoma 0.6% of the land is rated high; none of Harper County's is. Of the 6 counties that border it, 2 have more high-potential ground, Clark County, KS the most at 50.8%.
The map rates the ground, not the air in any home.
Local help
Harper County, Local resources
Radon testing and mitigation in Harper County
- Oklahoma's radon programDepartment of Environmental QualityOklahoma's radon program answers questions about testing, mitigation and the rules in Oklahoma.Visit the program’s page(opens in a new tab)
- Free and low-cost kitsAsk the program whether it has free or discounted kits, or compare kits you can buy.
- Compare kits
- See the Oklahoma directoryNo professionals are listed in Oklahoma yet. The state program can point you to registered testers and mitigators.
What it means
Harper County, Questions
Questions about radon in Harper County
Are radon levels high in Harper County?
No CDC testing statistics are published here for Harper County, Oklahoma yet. Of the 5 nearest counties with a figure, within 272 miles, the share of tests at or above 4 pCi/L runs from 6.0% to 44.7%.
Which counties border Harper County?
Harper County borders 6 counties: Woodward County, OK, Clark County, KS, Ellis County, OK, Comanche County, KS, Beaver County, OK and Woods County, OK.
Products
Harper County, Products
Testing a home in Harper County
No CDC figure names Harper County; the nearest county with one, Oklahoma County (152 miles away), reported 8.9% of its tests at or above 4 pCi/L over the 2006 to 2015 laboratory totals, the only reading nearby until a test of this home. Zone 3 is the lowest label, yet homes at or above 4 pCi/L occur in every zone: a short-term kit (2 to 90 days) is the quick first check in Harper County.
Test kits and monitors3
See every kit and monitor
Long-term kit
RL116 long-term radon test kit
- Lab fee extra
Method: Alpha track
In home: 90 days to 12 months
MonitorAEGTEST
HOUND-3699 radon monitor with a 2.1-inch touchscreen
- C-NRPP 2024/25: Not included
- Battery
- Alarm
- Screen
First reading: Within 1 hour
- See every kit and monitor Test kits and monitors
Test kits and monitors: 1 of 3
Explore
Harper County, Bordering counties
Counties bordering Harper County
Calculated by Radon411- Radon levels in Beaver County, OKEPA zone 2
0.0%at or above 4 pCi/L
Median 0.1 pCi/L · 1 test
- Radon levels in Woods County, OKEPA zone 3
0.0%at or above 4 pCi/L
Median 1.8 pCi/L · 1 test
- Radon levels in Woodward County, OKEPA zone 3
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in Clark County, KSEPA zone 2
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in Ellis County, OKEPA zone 2
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
- Radon levels in Comanche County, KSEPA zone 2
No CDC figure for 2006 to 2015; its page reads it against its own neighbours.
Harper County, Cities and towns
Cities and towns in Harper County
About 3,172 people live in Harper County by the Census Bureau's estimate for July 1, 2025, 74 fewer than in 2020 (−2.3%). Spread over its land, that is 3.1 people to the square mile. Its largest town, Laverne, has 1,189 residents, 37.5% of the total. Together its 4 incorporated places hold 71.5% of those residents; the other 28.5% live outside any of them. CDC publishes no radon test count for Harper County; across Oklahoma its counts for 2006 to 2015 come to 0.2 tests for every 1,000 residents (2025 estimate).
From Laverne to May, CDC publishes no figure by town: each reads Harper County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Laverne | 1,189 | −2.7% | 37.5% |
| Buffalo | 1,002 | −2.8% | 31.6% |
| Rosston | 50 | −2.0% | 1.6% |
| May | 28 | −3.4% | 0.9% |
4 incorporated places, as listed in the U.S. Census Bureau’s 2020 place reference files. Residents: U.S. Census Bureau population estimates for July 1, 2025 (Vintage 2025).
Harper County, Homes
Homes in Harper County
Harper County is a place of houses on their own lots: 86% of its 1,714 homes are detached single-family houses, against 73% across Oklahoma. The homes are older than Oklahoma's as a whole: half were built before 1965 (1980 for Oklahoma), and 40% date from before 1960. Owners live in 80% of the occupied homes (Oklahoma: 66%), so for most households a test and a fix are their own to order.
| Homes | Harper County | Oklahoma |
|---|---|---|
| Housing units | 1,714 | 1,763,036 |
| Detached houses | 86% | 73% |
| In buildings of 5 or more | 0% | 12% |
| Mobile homes | 11% | 9% |
| Built before 1960 | 40% | 21% |
| Built since 2000 | 9% | 25% |
| Middle year built | 1965 | 1980 |
| Owner-occupied | 80% | 66% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.