A California man was gored by a bison in a Yellowstone National Park campground Wednesday morning.

The 55-year-old man from Norco, Calif., was staying in Bridge Bay Campground near Yellowstone Lake. At about 11:30 a.m. he was taking pictures of a bull bison that was wandering among the campsites. When the two got to within about 10 feet of each other, the bison charged the camper.

The man received a puncture wound to the upper left thigh. He was treated at the Lake Clinic, then was transported by ambulance to St. John's Medical Center in Jackson, Wyo. His injuries are not considered to be life-threatening. The man's name was not immediately available.

It is the second time a park visitor has been injured by a bison this summer. A 50-year-old woman from Spain was tossed in the air by a bull bison in the Canyon area on June 24 while talking on a pay phone. She was treated for minor injuries.

A bull bison can stand 6 feet tall, weigh up to 2,000 pounds, and run at speeds up to 30 mph. Bison can be dangerous at any time, but may be more so during the next several weeks, which are the peak of their mating season.

Park regulations require people to stay at least 25 yards away from most animals and at least 100 yards away from bears and wolves at all times.