A lightning-caused wildfire northeast of Prospect has more than tripled in size since Wednesday.

Fueled by warm, dry weather and access issues for firefighters, the Blanket Creek fire has expanded to an estimated 180 acres, according to a Rogue-River Siskiyou National Forest news release.

No structures nor infrastructure are yet threatened by the blaze, located north of Bessie Rock in the Red Blanket Creek drainage near the Cold Springs trailhead.

The fire is being fought by 141 personnel, with more on the way, including three interagency hotshot crews, according to the national forest. Three crews of Type 2 seasonal firefighters, four engines, a bulldozer, several helicopters and an air-attack platform battled the flames Friday. Two more hotshot crews and more air support are expected to arrive by Saturday. The crews are based out of Joseph Stewart State Park at Lost Creek Lake, which remains open for recreation.

The efforts Friday focused on containing the north end of the fire using trails and roadways, according to the release. Crews were putting a handline on the west end of the fire and were scouting for fireline areas on the east side.

Saturday's forecast calls for relatively dry conditions, highs in the mid-80s and "breezy afternoon conditions," according to National Weather Service meteorologist Shad Keene. Humidity is expected to hover in the mid-20 percent range, which Keene described as dry, "but not crazy dry."

A heat advisory is anticipated for Monday through Thursday of next week, according to Keene. By Wednesday the mountainous regions could see highs of 100 degrees.

"That's when it gets really dry," Keene said. "Crews battling the fire will be dealing with some very hot conditions."

— Reach reporter Nick Morgan at 541-776-4471 or nmorgan@mailtribune.com. Follow him on Twitter at @MTCrimeBeat.