"She would stop for a few seconds and then bite again. Over and over. After a couple minutes, but what seemed an eternity, she disappeared."
Orr got up and headed back towards his truck, which was parked three miles below. He checked his injuries and noticed several puncture wounds on his arms and shoulder. After five or ten minutes, Orr heard the bear again.
"She either followed me back down the trail or cut through the trees and randomly came out on the trail right behind me.
"Whatever the case, she was instantly on me again," he wrote.
Wondering whether he'd survive a second attack, Orr once again put his arms around his neck, and kept his face tight against the ground.
"One bite on my forearm went through to the bone and I heard a crunch. My hand instantly went numb and wrist and fingers were limp and unusable," he wrote.
"The sudden pain made me flinch and gasp for breath. The sound triggered a frenzy of bites to my shoulder and upper back."
Orr stayed silent whole the bear continued biting him. He felt a gash open above his ear and blood trickling onto his face and eyes.
"I thought this was the end. She would eventually hit an artery in my neck and I would bleed out in the trail... But I knew that moving would trigger more bites so a laid motionless hoping it would end," he wrote.
The bear finally stopped biting and stood on top of him, crushing him. Orr didn't dare move and the bear finally went away.
Orr wanted to put as much distance as possible between him and the bear.
He reached his truck, put some jackets over the seat and drove to town. Along the way, he found a rancher and asked him to call the hospital.
Orr called his girlfriend and asked her to bring him clean clothes.
He made it to the hospital shortly after and had to ask an officer to undo his seat belt because his left arm was numb.
The officer was impressed that Orr had buckled up despite the circumstances, Orr said in his post.
He stayed in the hospital for eight hours, getting stitches on the puncture wounds an tears to his arms and shoulders. An x-ray showed he had a chipped bone in his forearm.
Orr had a five-inch gap on his head, which will leave a scar.
By Sunday morning, more bruises had appeared, some of them shaped like claws, on his lower back and butt.
"Not my best day, but I'm alive," Orr wrote.
State guidelines in Montana say that if a grizzly bear charges, the first option is to remain standing and try to use pepper spray. As a last resort, people can lie flat face down (like Orr did) or curl up in a ball.
People should not move or make noise until they are sure the bear has left.