Steven Bartley, 59, of Springfield, was at a campground in Montana, about five miles from the northeast entrance to Yellowstone when the bear approached his tent early Thursday.
Bartley said he received puncture wounds to both hands, some deep lacerations, and a broken bone below a thumb that required surgery at West Park Hospital in Cody, Wyo.
Bartley told The Billings (Mont.) Gazette that he and a friend were on their way to Gillette, Wyo., for an international motorcycle rally when the attack occurred.
"Apparently," Bartley told co-anchor Julie Chen on The Early Show Monday, "a large grizzly bear, maybe a rogue of some sort, attacked me through my (three person) tent. ... I was trying to get out of the tent and screaming and yelling. At that point the bear, as I reached up to unzip the fly to get out, the bear took a bite of my right hand. And I began swinging and hitting it as hard as I could and screaming in panic.
"At that point, the tent was collapsed around me. I kind of felt like I was enclosed in a sleeping bag. It then took my (left) hand and also took it in its jaws. So I began hitting it again with my right hand as hard as I could and screaming and yelling to get out.
"It went back to my right hand another time. That's when I could actually hear bones crunching.
"I'm just continuing to scream and yell and hit it as hard as I can, not actually even being able to see the bear. For some reason it quit. And I was rescued out of the tent by other campers."
Bartley added that he "couldn't see out because of the rain fly. And I kept yelling, 'Is anybody here yet? Is anybody here yet? I need help. I've been bitten by a bear.' And I could hear voices outside finally say, 'We're here, it's OK.' My understanding is nobody actually saw this bear that attacked me."
"It was just over so fast," Bartley told the Gazette. "I really feared for my life."
Bartley, a former Colorado law enforcement officer who now works part time for the Springfield parks and recreation district, told Chen he would "absolutely" go camping again, explaining, "It's all about knowing how to camp and how to deal with your own safety and what you do."
Doctors tell him he should get back 80 - 100 percent use of his right arm, the one that was more badly damaged, but it will be six-to-eight weeks until he knows for sure.
Careless food storage sometimes is a factor in conflicts between wildlife and people, but not in this case, according to Melissa Frost, spokeswoman for the Montana Department of Fish, Wildlife and Parks. Bartley's campsite was "spotless," she said.
"He didn't have any food in his campsite outside of a bear-proof container," she said. "He didn't cook at his campsite. The campground overall was very clean."
Given the bear's behavior, wildlife officials believe it was accustomed to people and their food, Frost said.