The Platte River Fire, which broke out Thursday afternoon in Jefferson County, grew to 31 acres with patches of containment by Thursday night, according to the Jefferson County Sheriff's Office.
The fire east of Foxton was staffed overnight, but not with air resources, officials said Thursday evening.
The blaze had started on private land and burned onto U.S. Forest Service land, they noted. No structures were lost or threatened as of Thursday night, deputies said. It started in the Dome Rock/Ramona Gulch area, around the 17000 block of West Platte River Road, near Foxton and Buffalo Creek.
The cause remains under investigation. A downed power line may have started the fire, according to the county sheriff's office.
Twenty-five homes had been contacted and people in about a 2-square-mile area evacuated, with evacuees being asked to check in at Conifer High School, law enforcement officials said.
North Fork Fire and Elk Creek Fire departments contributed to containment efforts. The U.S. Forest Service dispatched a helicopter, two air tankers and an air attack to help with suppression efforts on the ground, the agency tweeted Thursday.
The fires follow a week of dry weather and above average temperatures with more hot days to come. Temperatures were in the 90s all week in the Denver metro area.
While a slight cooling trend was expected Friday, hot and dry weather is expected to continue throughout the next week around the state. Denver is forecast to hit record highs in the 100s by Tuesday, according to the National Weather Service.
Fire danger remained high west of the Front Range where fuels are driest, the agency said.
Further west, the Colorado State Patrol reported shortly before 8 p.m. Thursday that eastbound Interstate 70 was closed at Silverthorne because of a new wildfire just south of the interstate, west of the Eisenhower Tunnel. Officials have named it the Straight Creek fire.
Fire crews recovered the remains of a burned out semi trailer near Silver Plume at mile marker 226. I-70 reopened Thursday night.
This is a developing story. Check back through the day for updates.