I don't know of a place that everyone swaps tires but I sent Sean at firstname.lastname@example.org
a Yamaha dealer in Buena Vista, Colorado a set of tires, a couple oil filters, air filter, couple tubes, set of sprockets and "O" ring chain. This is just north of Salida which is on the trail and I considered to be half way. I had scheduled an appointment at 8:00am and was done by 9:30. Both of us worked on the bike. He has a tire machine so was pretty quick. Also, cleaned and oiled the old filter and I packed it for a spare. Worked well for me.