Vertical steel reinforcing bars run from the bottom of the hole into the exposed pillar which serves as the antenna mount. The vertical hole was filled with concrete and extended monolithically to include the exposed antenna mount portion. Power and telemetry to this site are supplied by Southern California Edison from their colocated microwave facility. Mount Diablo is one of the most prominent peaks in the east Bay area. Located near the northern Calaveras, Concord, and Livermore faults, this site fills in an important gap in the Farallon-Sierra Nevada profiles, currently making it the most stable BARD station closest to the west side of the Great Valley.
Municipal utilities pass near the site and supply power and frame-relay telemetry.
The site was chosen for its good site sky visibility, for its availability of rock outcrop enhancing monument stability, and for its proximity to the Great Valley. Because it is located at one of the easternmost sites in the Diablo Range, it will provide valuable constraints on the total deformation accommodated between the Sierra Nevada range and the San Andreas fault system. S300 will become operational in October 1998. PTRB, located near the historic Point Reyes lighthouse at the westernmost point of land in the north Bay midway between the San Andreas fault and the Farallon Islands, will provide valuable constraints on deformation west of the San Andreas fault. MONB is located in a tectonically complicated region near the intersection of the Calaveras and southern Hayward faults, where the seismicity appears to step over along the Mission fault.