Along the way, I think you'll have better luck once you get closer to Moab.. like from Eagle on west. All the good stuff in the mountains is still pretty socked in with snow (not that snow isn't fun)
As for preruns while out in Moab, yeah you bet just show up in camp- at least someone will be running something every single day from Saturday onward... pretty unstructured though, won't take much to convince someone to go run something. See you in the desert!
82 fj40, 99 uzj100, 06 gx470
97 DR650, 05 525EXC, 06 TW200, 89 TW200, 09 TTR125, 07 TTR90, 07 CRF50