The Cinder Butte fire burning 10 miles outside of the town of Riley, Oregon, was burning 52,223 acres as of Saturday morning.
The fire is threatening archeological sites with strong cultural and historical significance to the Burns Paiute and Klamath tribes.
"We're working with our partners to identify those and be very respectful while working to contain the fire in those areas," said Nick Cronquist, a public information officer with Northwest Incident Management Team No. 10.
So far the fire is 15 percent contained. The blaze stayed within containment lines Friday night thanks to western winds blowing the fire into itself. That allowed firefighters to get in front of the fire and help with containment.
Still, about 300 personnel are fighting the fire. Officials expect 400 to be on the scene by end-of-shift Saturday.
The fire started off Highway 20 and was human-caused. The exact cause of the fire start is still under investigation.
"A lot of people, especially in eastern Oregon are going to be coming into the area due to the eclipse coming up, and we have very dry weather conditions," Cronquist said. "Please enjoy yourselves, but be very mindful fires can spread very quickly in these settings."
See a map of the fire region below.