Franklin W. Dixon 
End of the Trail [EPUB ebook] 

Hiking the Appalachian Trail with their friends, Chet, Phil, and Biff, the Hardys hit a snag when daredevil Biff gets hurt. The old mining town of Morgans Quarry is the nearest place for help. But even the run-down, isolated town turns menacing when two tough locals drop a bag full of money in front of the brothers! Joe and Frank are stonewalled when they ask about the money. The roads are washed out, the phones are down, and a crumbling mansion hides a gold mine of secrets. Every fork in the road leads to more danger…and everyone in Morgans Quarry seems bent on making sure the boys dont make it out alive