"The mountain is pretty steep," said Angeles National Forest District fuels officer Scott Lowden. "It's going to be nasty, but it sounded like it was holding [at the ridge]. There will probably be a couple days of mop-up."
Forest safety officer Ronald Ashdale said, "We knew this was a 'red flag' day.' It's going to continue to get warmer, probably 100 degrees by Friday. The conditions were right. [This fire] will fluctuate as the winds change."
Red flag days are when the conditions are perfect for forest fires: hot temperatures, low humidity and dry brush in the mountains.
The blaze, named the Station fire, started after 4 p.m. and burned 25 acres as of 5 p.m. Wednesday.
Helicopters were flying above the scene, and most fire personnel were on alert due to the fire's proximity to the Morris fire that started Tuesday afternoon in the Angeles National Forest above Azusa and Glendora.
Shortly after the Station fire started Wednesday afternoon Crescenta Valley Sheriff's Station personnel closed Angeles Crest Highway to traffic at mile marker 26.
"The highway will be closed probably at least until we knock [the fire] down," Lowden said.