Utah Fire Info reported the fire around 2 p.m. July 31.
Summit County spokesperson Derek Siddoway said the latest mapping shows it is 15.7 acres Aug. 1. Crews established a perimeter and had it 40% contained.
Local resources and state crews from the Ponderosa prescribed burn in the Uinta Mountains responded, Siddoway said.
The fire was on the west side of North Democrat Alley.
Utah Fire Info
This is a developing story. The cause is under investigation.