I suspect someone has moved this container as the most recent logs agree that it's not at the posted coordinates. Hopefully I'll be out in the area soon to correct things.
The following information is from the official website and the informational panel at the cache site.
To learn more, visit http://pboweb.unavco.org/
"The Plate Boundary Observatory (PBO), part of the EarthScope Program that is funded by the National Science Foundation, studies the three-dimensional strain field resulting from active plate boundary deformation across the Western United States.
"From a science perspective the PBO component of EarthScope is a geodetic observatory designed to study the three-dimensional strain field resulting from deformation across the active boundary zone between the Pacific and North American plates in the western United States. The observatory consists of arrays of Global Positioning System (GPS) receivers and Strainmeters which will be used to deduce the strain field on timescales of days to decades and geologic and paleoseismic investigations to examine the strain field over longer time scales."
It is acceptable to park in the nearby high school parking lot to visit this observatory.