Complex sentence: The U.S. response units were equipped with Willys MB jeeps and snowcats and the use of military gliders was contemplated, but these were quite useless in the alpine conditions, so rescue teams had to proceed on foot.
Split into simpler sentences: The U.S. response units were equipped with Willys MB jeeps and snowcats and the use of military gliders was contemplated. These means were quite useless in alpine conditions, so rescue teams had to go on foot.