The Hammer Fire, which reportedly threatened structures, started near Highway 21 and Warm Springs Avenue and spread into the foothills. No word yet how it started.
As of 8:30 p.m. the fire had been contained. Crews estimate it to have burned about 50 acres.
Two helicopters were called in to drop water on the fire to help keep it from spreading farther.
Crews from the Boise, Meridian, and Eagle fire departments and the Bureau of Land Management responded.
Traffic on Highway 21 was slowed through the area while crews were working.
BLM crews will stay on the scene overnight to mop up any hot spots.