I have been to several. Usually they cap registration at 300 but for Silverton I think they cap at 250 and there is still the club members that are there so the crowd is pretty good size. They lead guided trails but you have to sign up the night before at like 6pm all at one time so you have to have one or more trails picked out so if one fills up before you get to the head of the line you know what you want next. It is a kinda of pain but it does work. Most of the time I have gotten on the trail I have wanted for the day. The evening events crowd up so most people go and set up chairs early under the tent to stake out their spot. It is usually respected though it might get move a space or to if someone is not there to guard it. There is usually food a couple of nights, a couple of drawings, a show and grime "Jeep" show. They take Wednesday off and and it is vendor day/show day. In the past one day was pancake breakfast. If you plan to go plan your campground now and get reservations it is the busy time of the year up there and every and I mean every thing fills up!! Go with a relaxed attitude some things run smoothly others will not you just have to go with the flow. I have not been to a All4Fun at Silverton because it is an hour and a half away from me and I am up there at least once a year so I don't pay the fees for All4Fun to go there I usually go to the other places I don't always get to. I have always had a good time won something, spent money on raffle tickets, sometimes got wet, sometimes cooked in the sun but a good time was had. When thye post the registration opening date be ready they usually fill up in a few weeks to a couple of months. Read everything you can on the web site about it so you will have a good idea of the event offerings.