A fractostratus cloud (the remnant of a deck of stratus) hovers above the Mesa Laboratory of the National Center for Atmospheric Research in the foothills above Boulder, Colorado. Completed in 1966, the laboratory strikes many viewers as futuristic, but its design was strongly influenced by the ancient Indian cliff dwellings of Mesa Verde National Park in Colorado. With walls of reinforced concrete colored by locally quarried stone, the building harmonizes rather than competes with its dramatic backdrop, the monolithic sandstone slabs called the Flatirons. The NCAR Mesa Laboratory stands on a 400-acre (160-hectare) site maintained as a nature preserve. Mule deer and other wildlife range over the mesa and over the city-owned mountain parks and greenbelts adjoining it. Both the building and the park are open to visitors, and hikers are always welcome.