
Short-term kitFirst Alert
RD1 short-term charcoal radon test kit
- Lab fee included
Method: Charcoal
In home: 2 to 4 days
Locations and reports
EPA puts Sherman County in Zone 2, its middle radon zone, and only 1 radon test from it is on file with CDC (2019). Homes with elevated levels occur in all three zones, so only a test measures yours.
Data checked By Radon411Methodology
Highest bordering
10.0%
Wasco County
1 of 3 neighbours have 30+ tests, 2016
Nearest county
10.0%
Wasco County, 29 miles
Share at 4+ pCi/L, 30 tests, 2016
Ground above low
100.0%
37.7 pts above Oregon
Share of land USGS rates moderate or high potential
Tests reported
3
Too few for a share
2014
EPA radon zone
Zone 2
Moderate potential
1 highest, 3 lowest
EPA predicts 2 to 4 pCi/L indoors
Read a result for Sherman County
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
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
Sherman County, At a glance
Predicted: EPA radon zone
Sherman County is a
USGS geologic potential: Moderate across 100% of the county's area
Predicted: EPA Map of Radon Zones
Measured: tests reported to CDC
| Year | Share of reported tests at or above 4 pCi/L |
|---|---|
| 2014 | 33.3% |
| 2015 | 0.0% |
| 2016 | 0.0% |
| 2019 | 0.0% |
2019: 0.0%. Across these years the share ran from 0.0% to 33.3%. Each column counts radon tests reported to CDC that year, not homes.
Only 1 test was reported to CDC for Sherman County over 2019, and tests are often run on homes being sold or already suspected of a problem: so few describe neither the county nor this house.
Measured: CDC tracking data. Figure above: 2019. Measured data period: 2014 to 2019 (every CDC figure on file).
Sherman County, Compared
CDC's largest figure for Sherman County rests on 3 tests in 2014, 1 of them at or above 4 pCi/L, so each test moves its share by 33.3 points and no rank or comparison is drawn from it. Results reached as high as 4.8 pCi/L, with a middle value of 1.5 pCi/L.
Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L. Farther out, Hood River County (47 miles away) at 20.8%, Clackamas County (76 miles away) at 17.9% and Multnomah County (84 miles away) at 28.6% have figures too. Pooled across 35 Oregon counties, 21.5% of reported tests reached that level; across every county in the country with a figure, 31.2%.
Statewide for the same period, Union County reported the highest share (39.1%) and Deschutes County the lowest (6.7%). EPA's 1993 map puts Sherman County in Zone 2, its middle label: a predicted county average between 2 and 4 pCi/L. USGS geology rates 100% of the county's land moderate radon potential.
Pooled shares: Radon411's sum of CDC's county counts for one period.
Sherman County, Geology
USGS's geologic map puts all of Sherman County's mapped land in one class: moderate radon potential. All of it lies in the area the map calls Deschutes Umatilla Plateau, to which USGS gives a radon index of 9, in the moderate band (9 to 11).
| Area | The rock, in USGS's words | Potential | Radon index | Share of land |
|---|---|---|---|---|
| Deschutes Umatilla Plateau | Tertiary basalt, basaltic breccia, tuffaceous sedimentary rocks and tuff. Elevated uranium in soils. | Moderate | 9 | 100% |
Names, descriptions and indexes: U.S. Geological Survey, Geologic Radon Potential Map (2025). Shares: Radon411, from the map cut to the boundary.
Sherman County has more moderate-potential ground than Oregon as a whole: 100% of its land against 62.3%. Of the 3 counties that border it, none has as large a share of moderate-potential ground; Gilliam County comes nearest at 100%.
The map rates the ground, not the air in any home.
Local help
Sherman County, Local resources
Oregon Radon Awareness Program provides a FREE short-term radon test kit to those living in areas of Oregon where little radon testing has been done.
What it means
Sherman County, Questions
In 2019, 0.0% of the radon tests reported to CDC for Sherman County, Oregon were at or above 4 pCi/L, and the median reported pre-mitigation result was 1.5 pCi/L. Wasco County, the one bordering county with a figure in 2016, reported 10.0% of its tests at or above 4 pCi/L.
Sherman County borders 3 counties: Gilliam County, OR, Wasco County, OR and Klickitat County, WA.
Products
Sherman County, Products
No CDC figure names Sherman County; the nearest county with one, Wasco County (29 miles away), reported 10.0% of its tests at or above 4 pCi/L in 2016, the only reading nearby until a test of this home. In Zone 2 a short-term kit (2 to 90 days) is the quick first check in Sherman County; a long-term test tells the year-round average.
Test kits and monitors: 1 of 3
Explore
Sherman County, Bordering counties
14.8%at or above 4 pCi/L
Median 2.1 pCi/L · 27 tests
10.0%at or above 4 pCi/L
Median 0.8 pCi/L · 30 tests
0.0%at or above 4 pCi/L
Median 0.4 pCi/L · 1 test
Sherman County, Cities and towns
Sherman County is growing: the Census Bureau puts it at 2,051 residents on July 1, 2025, up 9.1% from 1,880 in 2020. Spread over its land, that is 2.5 people to the square mile. Its largest town, Wasco, has 457 residents, 22.3% of the total. Together its 4 incorporated places hold 64.5% of those residents; the other 35.5% live outside any of them. CDC's 3 reported tests for 2014 work out to 1.5 per 1,000 residents (2025 estimate), close to Oregon's 1.3.
From Wasco to Grass Valley, CDC publishes no figure by town: each reads Sherman County's.
| Place | Residents | Since 2020 | Share of residents |
|---|---|---|---|
| Wasco | 457 | +9.3% | 22.3% |
| Moro | 403 | +8.9% | 19.6% |
| Rufus | 292 | +9.8% | 14.2% |
| Grass Valley | 170 | +11.8% | 8.3% |
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).
Sherman County, Homes
Of Sherman County's 979 homes, 63% are detached houses, against 63% across Oregon; 30% are mobile homes. The homes are older than Oregon's as a whole: half were built before 1956 (1980 for Oregon), and 53% date from before 1960. 67% of occupied homes are lived in by their owner (Oregon: 63%); in the rest a tenant can run a test, but a fix is the landlord's to make.
| Homes | Sherman County | Oregon |
|---|---|---|
| Housing units | 979 | 1,838,631 |
| Detached houses | 63% | 63% |
| In buildings of 5 or more | 2% | 17% |
| Mobile homes | 30% | 8% |
| Built before 1960 | 53% | 23% |
| Built since 2000 | 14% | 24% |
| Middle year built | 1956 | 1980 |
| Owner-occupied | 67% | 63% |
Census Bureau, American Community Survey, 2019 to 2023: estimates from a sample of homes, looser for a small place. Shares by Radon411.