You may think you know what the Thunder Mountain Line is. Rumor has it, it's a quiet weekend train ride alongside the Payette River, with the occasional Old West bandit pantomime tossed in to titillate a customer base of almost exclusively children, parents and old folks. But should those tots look down toward the Payette, without fail, they'll receive their first and most traumatic anatomy lesson, thanks to the dozens of river-raft derelicts who moon and flash the TLM like doing so enters them into the Publisher's Clearinghouse Sweepstakes.