Drive out on Lake Mary Road about 8 miles and turn left at the
sign "Marshall Lake/N.P.O.I." N.P.O.I. stands for Naval Prototype
Optical Interferometer which is at the Dark Sky Site. On the way in-you
will see Lower Lake Mary. About a mile past the turnoff-you will see
picnic pavilions and parking for Upper Lake Mary.

Here are photographs

http://s144.photobucket.com/albums/r168/flagstaffhikingclub/?
action=view&current=66f3305a.pbw