Waterton Canyon in Jefferson County reopened to recreation Sunday as firefighters continued to contain a small wildfire in the area, authorities said. The small fire started Saturday around 2 p.m. and burned about an acre-and-a-half, according to West Metro Fire Rescue. Authorities on Saturday closed the canyon, which is a popular area for hiking, biking, running and other outdoor recreation southwest of Chatfield State Park, to everyone except emergency crews. Heavy rain on Saturday night helped to keep the fire small, according to the Jefferson County Sheriff’s office. The fire did not cause any evacuations and no structures were threatened.