On August 10, 1972, in Rifle, Colorado, between Grand Junction and Glenwood Springs in the Grand Hogback Mountain Range, at 11 am a group of 35 construction workers and 64 temporary helpers, art-school and college students, and itinerant art workers tied down the last of 27 ropes that secured the 200,200 square feet (18,600 square meters) of woven nylon fabric orange curtain to its moorings at Rifle Gap, 7 miles (11.3 km) north of Rifle, on Highway 325