In July and August, when the daytime temperatures can reach the 90s, Boulderites take to tubing in Boulder Creek—especially near Eben G. Fine Park at the mouth of Boulder Canyon (Junction of Arapahoe and Canyon boulevardslvds.) The Conoco (1201 Arapahoe Ave., at Broadway. 303/442-6293) gas station sells inner tubes ($12) and Boulder Creek is less than a block away. The station is open from 10 AM until 9 PM weekdays and Saturday, and 10 AM-8 PM Sunday.