To the north of the park, at the base of Fairmont Butte, is a tuff quarry. Tuff is compacted volcanic ash, not to be confused with tufa, which is calcium carbonate. Tuff can be mixed with cement to make concrete more "tough." This site was quarried for the construction of the Los Angeles Aqueduct, which runs underneath the valley just to the west of the Reserve. Under the leadership of William Mulholland of the Los Angeles Department of Water and Power, 5000 men worked for five years to complete the project in 1913.
The Aqueduct stretches 238 miles from the Owens Valley to Los Angeles. Los Angeles could not otherwise have exceeded a population of 500,000.
The 18’ tower atop Fairmont Butte was built for a wind generator in the late 1960’s, and was used for only one week before it was vandalized.