Lets talk about camping and Mountain Biking

I would do a Google search for `______ mountain biking' and put in the blank the State you are interested in researching. I would start with Minnesota. Deal with the campgrounds after you find a trail.
www.singletracks.com seems to pop up frequently when doing that search.
We're at the age where we prefer paved bike trails; downhill both ways!

If you ever make it to Alabama check on Oak Mountain State Park. They have a great campground and from those I've spoken with an awesome trail system for bikes. I no longer mtn bike due to both knees are gone but I've walked some of the trails snd they are in great shape. Check out Anniston, Alabama also they have just completed phase one of a mountain bike park and are now working on phase 2 and will start another park soon. There are several campgrounds within 20 minutes. Good luck, have fun and hit a few trails for me.

We used to ride everywhere: flatlands, hard packed sand, rolling hills and wooded trails. Just depends on your health and stamina. We didn't just go places to mountain bike. We bought them so we could bike anywhere.

There's a BLM CG right among the MTB trails north of Fruita (also called 18 road). A variety of loops from four to ten miles in length. Nothing terribly difficult. A couple of loops are challenging because of exposure. Ride right from your campsite, do a loop or two, go back for lunch, and then out for more riding.

Dead Horse Point near Moab has 17 miles of singletrack, mostly easy to lower intermediate, that you can ride from your campsite. Some great views over Canyonlands.

Moab has really expanded their singletrack. In the old days (5-7 years ago), most of the riding was on jeep trails. Since then, they've put in a couple hundred miles of singletrack. Between our visit in May and October, they added 25 miles of singletrack out there. We can't get out there enough -- the riding is just great. Check out this link. We usually start out on the easier trails of Klonzo, then head to the Brand Trails and Klondike Bluffs area. Just last month, we tried out the new Navajo Rock area. Since then, they've added six more miles of trails there -- something to explore next spring! There isn't any camping right at these trails, but plenty of camping in the Moab area. This is worth the drive from wherever you are. Every time I visit, I meet people from Europe who have taken a trip over here just to ride Moab.

Another great riding area is around Salida, CO. Great trails right out of town -- ride your bike then park and have a meal with your favorite beverage. Check out the maps section of this link. No riding from a campsite, but easy access. There's also a loop ride on the Rainbow Trail using the Silver Lakes Road as the uphill section. One can boondock along parts of the Silver Lakes Road or camp at O'Haver Lake NFS CG.

Near Bryce Canyon, camp at Red Canyon NFS CG, ride up the paved bike path and take the gravel road to the top of Thunder Mountain Trail. This singletrack is on NFS lands, so legal to ride, but it's like riding through Bryce Canyon NP. You'll end up stopping to take in the view or you'll crash since you'll be sightseeing rather than watching the trail. Several other trails in the area are rideable from Red Canyon CG.

Outside of the NP boundary, the Rainbow Rim Trail on the north rim of the Grand Canyon has good views. Plenty of boondocking in the area, or stay at DeMotte NFS CG.

Other places we enjoy riding: Bend OR, Telluride CO, Durango CO.

For ideas on where to ride in UT, check out this page.

We've ridden a lot of different places, so it's hard to keep track of where all the great trails are.

Everywhere ;). But for parks with amazing mountain biking onsite. Here are some:

Sweetwater San Diego Ca

Curt Gowdy near Cheyenne

Tapo Canyon Simi Valley CA

Pretty much anywhere in Mammoth Lakes CA

Asheville NC

Moab Ut

All of the above are places where you can walk out of your RV throw your leg over the top tube and start riding from camp. There are hundreds of other places where you can do the same but with added riding on city streets to get to the trail.

Where do you guys camp that feature Mountain Bike trails? I have camped a few times at Mohican Adventure in Ohio that features around 30 miles of excellent MTB trails. Locally we also have Findley State Park as well as West Branch state park that have good trail networks.
Hopefully this spring we are going to tow the rig down to Markham Park in Ft Lauderdale to ride the trails and enjoy early spring sunshine.

Virtually anywhere you want to camp in the Sierras, California or Nevada, is a short distance (if any distance) to mountain biking. Lots of single track and jeep trails.