PINEDALE, Wyo. (AP) — A new fire is threatening homes in western Wyoming.

The Chall Creek Fire started Sunday afternoon west of Merna, about 30 miles west of Pinedale, and has spread to 140 acres.

Two crews and a helicopter that had been working at the Horsethief Canyon Fire south of Jackson were among those assigned to fight the new fire Monday.

The Horsethief Canyon Fire is 57 percent contained. Fire managers say existing fire lines, including those protecting the town of Jackson, held well despite gusty and erratic winds on Sunday. They felt confident enough to release the crews to fight the Chall Creek Fire.

Meanwhile, a fire that destroyed 36 homes and cabins on Casper Mountain and forced 400 people to evacuate was fully contained Sunday. The cause is still under investigation.