Two forestry surveyors are recovering in an Alberta hospital after being attacked by a grizzly bear Saturday.

Moira McLaughlin and Daylon Johnson, both British Columbians in their 20s and working for Alberta Sustainable Resource Development, were collecting data on the mountain pine beetle in a remote area south of Grande Prairie, Alta.

"We were going down a steep slope and the bear came up behind Daylon and knocked him on top of me. He bit the back of Daylon's leg and bit my hand when I went to cover my face," McLaughlin told CBC News on Monday.

"I was very scared and I guess I was just surprised because he came out of nowhere and attacked [Johnson] from behind."

Johnson said he started hitting the bear and it took off on its own.

"We were just kind of quiet and sat there and let it get a ways a way. Then we got up and went the opposite way it went."

The surveyors radioed for help and were picked up by helicopter. They required surgery for their injuries.

The Prince George Citizen reported Monday that the pair was from Prince George, B.C.

Annette Bidniak, a spokesperson for the department, told CBC News the workers accidentally walked over the bear's snow-covered den.

"There's 3½ feet [just over a metre] of snow in that area, the den was built into the side of a hill and there was a fallen tree on top of it. So anyone walking over it would not have known they were walking over a bear's den."

Wildlife officials have closed off the area, but say no action will be taken against the bear because it was simply defending its den.