Taking your two posted interests as a guide (geocaching & Bleeping-study), it appears that you are an ambitious and active kind of person.
Lots to explore here at WTT as well. Enjoy!
Being mostly a flat-lander for the past twenty years, I can only say… "Whew!"
Having spent an entire 12 month cycle in a semi-wilderness (chop wood, carry water, trench the tent, walk if you want to get there) area of the Sierra foothills, I have an inkling of what you may enjoy for recreation. I've explored some of the hard rock tunnel mines and many hydro/dredge/sluice mining sites along the west branch of the Feather River between Magalia and Sterling City http://maps.google.com/maps?q=Magalia,+CA,…ap&ct=image
Hope you enjoy your visit here at WTT and decide to frequent our pages as interest or need dictates.
Best Regards