A teenage staffer at a Colorado camp fought off a bear after waking up to find the animal biting his head and trying to drag him away.

The 19-year-old woke up at around 4am on Sunday to a “crunching sound” with his head inside the mouth of the bear, which was trying to pull him out of his sleeping bag as he slept outside at Glacier View Ranch 48 miles (77km) northwest of Denver, Colorado Parks and Wildlife spokeswoman Jennifer Churchill said.

The teenager punched and hit the animal and other staffers who were sleeping nearby yelled and swatted at the bear, which eventually left, she said.

The staffer, identified only as Dylan, was treated briefly at a hospital and released.

The teen told KMGH-TV that the bear dragged him up to 3.5 metres (12ft) before he was able to free himself.

“The crunching noise, I guess, was the teeth scraping against the skull as it dug in,” said the teen, who teaches wilderness survival at the camp owned by the Rocky Mountain Conference of Seventh Day Adventists.

Dylan and the other staffers were near teepees where 12- and 13-year-old campers were sleeping. None of them were hurt.

Black bears are not usually aggressive but have attacked several people in the western US in recent weeks.

A woman and her dogs were attacked on Tuesday after they apparently surprised an adult bear and her cub in a huckleberry patch in the Idaho Panhandle national forests.

Last month, black bears killed two people in Alaska in separate attacks.

Sixteen-year-old Patrick “Jack” Cooper of Anchorage was killed after he got lost and veered off a trail during a mountain race south of Anchorage. Mine contract worker Erin Johnson of Anchorage died and her co-worker was injured in a mauling about 275 miles northeast of Anchorage.

Earlier this month a boy aged 11 shot a bear that was charging at his family who were on a fishing expedition in Alaska.

Black bears will defend their young and have been known to paw and bite tents with food inside. After the Colorado attack wildlife officers did not find any food that would have attracted the bear so they have set bear traps in the area and plan to continue a search with dogs on Monday.

The bear’s behaviour was so atypical that any bear found in the traps in the next few days will likely be euthanised and officials will test later to see if it was the same bear involved in the attack using DNA evidence, Churchill said.