The site is located in Marin County, California and is situated 12 miles southwest of Inverness and 30 miles northwest of San Francisco, California (see attached map).
On 17 April 1943, the War Department acquired 8.91 easement acres from Joseph V. Mendoza. The total acreage acquired was 8.91. It was used by the Army's Harbor Defenses of San Francisco as an access road and as a location for a datum point, which is a reference point of known or assumed coordinates from which calculation or measurements may be taken. Usually there is a marker or landmark from which survey measurements could be taken.
Since Army usage was terminated, both sides of the 40 ft. road have been used as pasture land for cattle. The Datum Point marker has been removed. Presently, the site is part of the Point Reyes National Seashore.
