I have brazenly plagiarized this puzzle from SpursUp11's cache (GC67KVK) in Springfield, Virginia. I found SpursUp11's puzzle cache on my recent visit to VA, and I thought it was pretty cool. SpursUp11 cites inspiration from kanchan's cache GC4N5VE in Belmont, CA and others like it such as GC5E9CD in Little Rock, AR and GC5THPY in South Carolina. (I saw a familiar local geocacher's name in the logs for the South Carolina one, Brotherseldom says he's seen this puzzle in CA before... he hasn't logged the northern California one, so there must be another one around here somewhere, but I haven't seen it myself.)
Hints for the puzzle might be found on the other listings. 
Note added 2016-01-01: Congratulations to Brotherseldom himself for the FTF, 29 minutes after the cache was published! I don't usually add the FTF into the cache description, but this coincidence can't go unremarked upon. I couldn't have picked a more amazingly appropriate player for the honor! Now I just have to search through all of Brotherseldom's puzzle cache finds, by Bajatym, that he was FTF on...!... >800 "Mystery" cache finds, I don't think so! One of these days I have to learn to use GSAK....
Note added 2016-01-02: Congratulations ALSO to Bajatym for the FTF! Again I couldn't have picked a more amazingly appropriate player for the honor, since he is the owner of the other similar puzzle GC530M2 in Southern California! My apologies for misinterpreting Brotherseldom's log yesterday, I thought he meant he met Bajatym at the other puzzle when he was FTF on it....