Seneca is a city in Grant County, Oregon, United States. It is located in the Blue Mountains about 23 miles (37 km) south of Canyon City, on U.S. Route 395, on the edge of the Malheur National Forest. As of the 2020 census, Seneca had a population of 165.

From Wikipedia, licensed CC BY-SA 4.0 · facts via Wikidata (CC0)

Town numbers

ZIP code97873

Area code541

Living in Seneca

Work & commute in Seneca

Full picture →

Most working residents leave Seneca for work: only 2% work in town. The top destinations are John Day (8%), Portland (8%) and Bend (6%). Half commute less than 116 miles.

John Day

Portland

Bend

Dayville

2%Work in townlive and work in Seneca 116 miWhere do people commute?the commute map 15Jobs based herea commuter town

Census LEHD 2023 · ACSWork & commute in Seneca →

Health in Seneca

Compared with Oregon

2better than OR·7worse

of 26 measures CDC estimates. The other 17 are too close to call.

Conditions 7▼ 5 close Habits all close Care 2▲ 5 close Mind all close

BetterToo close to callWorse

What stands out

77.6%More adults treating high blood pressureOR 71.4% · better 87.5%More adults getting cholesterol checkedOR 84% · better 12.5%More adults who have had cancerOR 8.9% · worse

Care nearby

Blue Mountain HospitalJohn Day · 19.5 mi · ER · rural critical access

Spray Field OfficeSpray · 62.9 mi · sliding-scale fees

Primary careShortage · county-wide

DentalShortage · county-wide

Mental healthShortage · county-wide

CDC PLACES 2025 · modeled estimates for adults · CDC's estimate for Seneca · CMS · HRSAHealth in Seneca →

Natural hazards in Seneca

Very high

Expected storm and flood damage is higher than in 90% of U.S. communities.

🌊 Inland flooding🔥 Wildfire⚡ Lightning

0Does Seneca flood?no paid flood claims on record NoneDisasters that paid out hereof 13 declared for Grant County

FEMA National Risk Index December 2025 · OpenFEMANatural hazards in Seneca →

Climate in Seneca

Full climate →

Seneca has chilly winters and pleasant summers, with very little rain. A typical July afternoon reaches 83°, a January night drops to 16°.

38° / 17°Winter

54° / 28°Spring

79° / 41°Summer

58° / 28°Fall

Does it ever freeze?In about 100% of years.Frost →Is it warmer than it used to be?+1.3° vs. the 20th century.Then & now →

NOAA U.S. Climate Normals, 1991–2020Climate in Seneca →

Schools in Seneca

All Seneca schools →

B⁺

School Grade B+

The public schools Seneca’s kids attend, from kindergarten through graduation, outperform 68% of Oregon’s districts on state tests and graduation. Among towns with similar incomes, they rank near the top.

DistrictJohn Day SD 3Schools1

Seneca Elementary SchoolElementary · Grades K–6 · 12 students

School data from the U.S. Department of Education (NCES, EDFacts). The School Grade is our own summary of state test results and graduation rates, graded within OR. Ratings are from neighbors.