To reach the cache, park at Mile 90 at the Riprap parking lot on
Skyline Drive in Shenandoah National Park. Take the AT for a short
distance and take a left onto the Riprap Trail. You will reach the
cache in about 1.8 miles.
The area along the Riprap Trail in Shenandoah National Park
demonstrates some great opportunities to discover some great
examples of quartzite rock. The story of the formation of the
Calvary Rocks would date back to over 500 million years ago. An
ocean (named the Iapetus) spread across the eastern portions of the
United States, depositing sediments as the tides rose and fell. The
Appalachian Mountains formed through the moving of plates. Lava
flows and volcanoes of the Catoctin Formation carried the sediment
to the ocean. As the water rose, river systems carried a thick
layer of sand and mud to new heights and formed thick
sediment-filled lagoons. Several thousand feet of silt and sand
filled the waters and developed these mountains into beds of white
quartz sandstone. The heat and pressure that helped form the
Appalachians created highly fused and pressured rocks, like the
Erwin white quartzite you will find here.
You can see other examples of similar quartzite in Shenandoah
National Park at the Rockytop Overlook, Turk Mountain, and
Blackrock Summit. 
From the coordinates, you will get some great views. To lay
claim for the cache, please do the following:
1) Look closely at the rocks to analyze the colors. Email me
three colors that you see in the rock formation and how tall you
would estimate the majority of the boulders pictured to be. Do not
post the answers here.
2) Post a picture of yourself with the rocks, view, and GPS in
view.
Enjoy the trail and the scenery!