April 1 and 2, 2017...
http://stumpjumpers.org/desert100/ in central Washington state,
2-day event starts with a poker run on Saturday (3500 +/- people) and a 2-lap 100 mile desert race on Sunday, typically around 800 -1,000 participants for it. Right smack dab in the middle of nowhere in central Washington state. I believe it's the largest motorcycle-only desert race in the country. (even uses a smoke-bomb start!)
Lots of West Side dealers (Seattle, Tacoma, etc) bring trailers and sell parts and services. TBT Racing has been there in the past along with Factory Connection (I think that's right) doing fork and shock service. There's also been a KTM dealer giving test rides in the past. Live bands, food trailers, etc.
I've missed the last several years but it's quite a show.