My bikes ('99 KX250 and '04 KDX200) have their offroad registration stickers for here in Colorado. If I go to another state, CA in particular, will I be legal to ride there, anytime of the year, or are there hoops that I have to jump through?
No problem. California, and I believe all other states, honor ORV registration from other states. I just did some riding at an OHV park in California with Washington state tabs, no worries.
hmm, wonder about those of us from states with no tags or titles on our bikes... we don't even require a license on a personal trailer (but they will sell you one $100 to lessen out of state problems).
You can get an out of state sticker for your bike. Also to avoid hassles it's a good idea to carry your drivers license with you when you ride to prove you really are from out of state. If I remember correctly the out of state bike sticker is around $20. I think I picked one up at the CA DMV but it's been awhile so I may be wrong on that.