It took $2.45 million, 80 men and 18 Caterpillar tractors working with 28 engineers and others from the U.S. Bureau of Roads to build the 35-mile road to the top of Kitt Peak National Observatory in 1960. It was a treacherous job. "Make one wrong turn and you're in trouble," said a dozer operator.
Building the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: A dozer operator tackles tree stumps and rock.
Dan Tortorell / Tucson CitizenBuilding the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: Bulldozers operate on treacherous, unstable material blasted from the the face of the mountain.
Dan Tortorell / Tucson CitizenBuilding the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: A dynamite blast helps shift the dirt and rock before the bulldozers finish the job.
Dan Tortorell / Tucson CitizenBuilding the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: Workers slip explosives into holes to blast away rock.
Dan Tortorell / Tucson CitizenBuilding the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: A truck eases down the early primitive road from near the top. The first telescope on the mountain, the 36-inch, can be seen in the background.
Dan Tortorell / Tucson CitizenBuilding the road to Kitt Peak National Observatory

Building the road to Kitt Peak National Observatory in May, 1960: A jackhammer operator pounds away at the rock face.
Dan Tortorell / Tucson Citizen