The blaze broke out Saturday night. A section of the 111 between Tram Road and Overturn Drive, which is the major way into and out of downtown Palm Springs, remains closed as of Sunday morning.
Authorities said the fire has scorched about 450 acres and is 15 percent contained.
Steep and rugged terrain and winds of up 35 mph are hampering firefighting efforts.
No injuries were reported and no structures were threatened.
Officials said 150 fire personnel were on site.
The cause of the fire was under investigation.