JACKSON - A well-known mountain guide has been cited for driving a snowmobile over the frozen Jackson Lake inside Grand Teton National Park.

Park rules permit only ice fishermen to ride snowmobiles onto the lake in northwest Wyoming.

A video posted on several Web sites recently showed four skiers crossing the lake - two riding the snowmobile and the other two being towed behind on skis.

Grand Teton spokeswoman Jackie Skaggs said that following an investigation rangers cited mountain guide Stephen Koch for towing skiers with a snowmobile and using a snowmobile on the lake for purposes other than ice fishing.

Koch offered a public apology, saying he suffered a lapse in judgment.

But he was subsequently fired this week from his job at Exum Mountain Guides.