The 27-year-old Phoenix man was hospitalized with injuries to his legs and pelvis after being hit Tuesday by the 30-ton boulder, the Coconino County Sheriff's Office said. Authorities had no update on his condition Wednesday morning, and the road remained closed.
The man and four others were trying to get to the top of Mount Elden near Flagstaff to work on a radio tower when a large boulder blocked their path. The group tried to move it when another boulder that a fire official described as being "as big as a Volkswagen" slid down the mountain slope and hit the man.
The workers called for help but were able to remove him from underneath the boulder before responders arrived.
"I'm not exactly sure how they did it," Summit Fire Department Capt. Brian Parker said. "Just the fact they were able to get it off him was impressive, and it made our job a whole lot easier. Anytime there's any kind of crushing injuries like that where they're trapped, the sooner the better to get them out."
A photo of the scene showed a strap around one of the boulders, but Parker said he didn't know if the group used that, their truck or their bare hands in trying to move the first boulder that was blocking the road or the one that later fell on the man.
Thunderstorms washed out parts of the road, preventing anything but four-wheel drive vehicles from accessing the site. The man ultimately was transported down the mountain in one of the sheriff's office vehicles.
Parker said the man was alert the entire time, answering questions and talking to responders on the scene.
"He was obviously scared and in pain," Parker said.
Coconino National Forest spokeswoman Brienne Magee said crews will assess the road once the rain eases and eventually will move the boulders.