The Weiser Knoll Fire ignited on Sunday afternoon due to a mechanical fire on a trailer being towed, Fremont County Fire Protection Chief Ron Wempen told County 10 News. The Weiser Knoll Fire started Aug. 9, 2026, southeast of Lander and by Monday afternoon had grown to more than 13,000 acres. Nevertheless, the Weiser Knoll Fire’s estimated acreage grew dramatically over its first 24 hours and reached 13,350 acres with no official containment by 3 p.m. on Monday. A Fremont County evacuation order remains in place for the Twin Creek drainage and portions of South Pass. But the Weiser Knoll Fire is the largest incident of the year, surpassing Sheridan County’s Lumin Fire, which was extinguished in late July.