I also recall hearing about the operation to Tacoma early in D&SNG history.
If you are talking about revenue freight and not freight trains, Ah! Wilderness and now the USPS can either contract the D&SNG for service or fly supplies in by helicopter. I'd think that moving horses or ATV's in by chopper would be prohibitive.
I also seem to remember hearing that a box car of concentrate samples from around Elk Park (mined in the canyons to the east) were taken out when gold prices were in the $800/oz range 10-15 years ago. I've never heard from anyone who could confirm or deny the rumor.