Most of the emails to the club are asking camping questions.  With all the camping info sprinkled throughout this site, we've decided to get it all condensed on one page.
If you are coming to Mammoth to camp and find any of this info useful, please spread some money around town as thanks.  Helping the local economy helps the club - and we appreciate the support!
First of all what kind of camping are you interested in, we have all types:
1. Free dispersed -
2. Free campgrounds -
3. Pay campgrounds -
4. Pay RV resorts -
1. Dispersed (free).
Dispersed camping is bringing up all your gear, trailers, whatever, and finding a spot along a dirt road that is good for camping.  It's allowed all over the Mammoth area except in a few spots like Red's Meadow and the Mammoth Lakes basin.  The most you'll get in a dispersed spot is a fire ring or some old rickety picnic table someone hauled out long ago.  But, you also can get a nice hide-a-way next to a flowing stream where no one comes around to bother you or collect nightly rent.
Best dispersed spots:
Out behind Shady Rest Park.
Out along the scenic loop.
Up in an aspen grove halfway up to Laurel Lakes.
Almost anywhere between Mammoth and June Lake.
Up in the Glass Mountains.
At or near the Bald Mountain cabin.
2. Free campgrounds.
Wow!  With campgrounds in Mammoth going for $21 and more per night, free starts looking good.  Plus the pay campgrounds double as ATM machines for an out of the area corporation.  Sure, Mammoth gets a slice of the tax, but the campgrounds are going downhill compared to when the USFS ran (and upgraded) them.  At a free campground you can expect on a nice level spot for camping, easy access, a fire ring, table, outhouse and free ass napkins, and sometimes water - but not usually.  Some have hosts, some don't.  All free campgrounds are OHV friendly provided you don't act like a fool around camp.
Best free campgrounds in order:
Hartley Springs
Big Springs
Glass Creek
Deadman (upper and lower)
Sagehen Meadow
Taylor Canyon
Aspens/Cold Spring (not officially recognized but closest to Town of Mammoth)
To locate the free campgrounds pick up a free CTUC map in town or try searching online.
And beware!  A free campground has wide open access to your next OHV expedition.  A little careless planning and you might end up in Death Valley, or worse, in BFE Nevada.
3. Pay campgrounds. 
Pay campgrounds used to be a public asset.  Fees were reasonable and money was put back into each location.  Now they've been privatized, for better or worse.  Fortunately we grew up with them and know the best spots.
None of the pay campgrounds are truly OHV friendly unless you are riding a dual sport.  But there are a few worth mentioning for OHV access and they are Sherwin Creek, Shady Rest campground, and Oh Ridge over at June Lake.  At these campgrounds you may be able to push your bike a few feet to a legal dirt trail, we won't mention specifics for fear of closure.
Moving on we recommend the following pay campgrounds in Mammoth:
Sherwin Creek (OHV friendly)
Coldwater Creek (OHV unfriendly, fishing friendly)
Lake George (OHV unfriendly, fishing friendly)
There are many more.  At a pay campground you can expect to pay $21 and up per night.  Flush toilets are available but some are being replaced with pits - moving back in time due to privatization perhaps.  Plenty of hosts, some pleasant some confrontational.  Fire rings with BBQ sidecar, creek and lake spots, plenty of other campers and hungry bears too.  They are trailer and RV friendly but no hook-ups except for one or two over at French Camp near Tom's Place.  They can all be reserved online at
Final word on pay campgrounds - check out Rock Creek Canyon, Convict Lake, June Lake Loop, Lee Vining canyon, and Lundy Canyon for the goods.   And Red's Meadow - Red's is a world removed from Mammoth.   Someone needs to get the Red's bath-house up and running!
4. RV resorts/sites
They are spendy ranging from $25-$60/night.  Below are the closest ones to Mammoth.
Mammoth Mountain RV Park, 760-934-3822
McGee RV Park, 760-935-4233 
Crowley Lake RV Park, 760-935-4221
Pine Cliff RV Resort in June Lake, 760-648-7558
None of the RV resorts are very OHV friendly except for Pine Cliff if you stay on the operator's good side.  The RV park in Mammoth you better plan on trailering but there are a couple known motorcycle single track about if you can sniff them out.
Mammoth dirt trails/roads have no red sticker restrictions!
7-15-2012 update
OK, after hearing a hissed "smart-ass" from yet another CLM employee at a paid campground (see #3) we offer another call-out to this fine organization.
How can we get in on the free storage of recreational vehicles on public lands?  Is it an employee's only perk?  Just asking because at French Camp RV's are stored winter long under ragged tarps.  Some of us are running out of room at home.  Just asking.  Use the 'contact us' button.
When prompted by a large group of us over at Sherwin Creek campground the CLM campground attendants explained that the flush toilets were being replaced by pit toilets "because the Town didn't want to fix the sewer connection".  WTF.  Now the Town is responsible?  Yeah, right.  Meanwhile we watched USFS tractors and laborers put in the new pit toilets, on the public dime, and CLM continues to rake in the dough.  Nice racket.
Upon departing, we were told, "well, last year the flush toilets didn't really work that well anyway". 
Uh huh, we know that toilets don't run forever, they need to be fixed and maintained - but to rip out entire bathrooms and replace them with pits... no one in their right mind would ever do that.
By the way, your new pit toilets smell like shit.