Buttercup is the area bordered by the all american canal on the east, I-8 to the north and a western boundry where the dunes suddenly turn into desert scrub. So in many ways it's a mirror image of Glamis

It's a relatively small area but has quite a bit of pavement and hardpack for camping. From the parking circle at the main campground you can head kind of southeast and there's a sand highway that leads through hardpack to the "first valley". Getting street trucks through here is no problem at all, you may have to air down a little but I normally tow my trailer through there with full pressure and have no problems as long as you keep the momentum up.
In the first valley of Buttercup you'll find the south dunes comp hill to the north, it's much steeper than Glamis comp and still gets a lot of "old time" style racing and families hanging out. Along the back of the valley there's a jeep trail at the base of the dunes where you can catch some air on a few small jumps and to the south east of comp there are a few really good jumps in the dunes that are visible from the valley and the top of comp.
Comp at buttercup also has a few good jumps scattered around it and it's not uncommon to see a group of predator cars jumping as they go up the hill, jumping a lip at the top, and then pulling a big jump off a lip as they start down the hill. One thing to watch for is that in the summer and begining of the season there's almost always a nasty ridge at the top of comp with a sudden drop off when you get up there.
There are some big bowls at buttercup and they're tucked in kind of north west of the first valley. There's one that's simply amazingly huge if you head directly west out of the valley and go over two ridges. It's easy enough to get to I've had my truck there on many occasions and have even railed the lip in my truck a few times.
South of the first valley is a set of very soft dunes that can be fun but you have to be carefull in. South of those is the second valley followed by more dunes and eventually a well worn sand highway that marks the mexican border. There are small and large concrete markers along the southern edge of this road marking the actual border.
I've yet to explore the dunes east of the valleys but I'm told there's a lot more there than it looks because the mexican border slants south so it's a much larger area than the western edge of buttercup.
Gordon's is the area just north of I-8 and the all american canal with western and eastern boundries much like Glamis. When you first enter the "Dunebuggy flats" camping area you cross over the canal where it suddenly makes a sharp turn east and follow I-8 across the dunes where it then makes a sharp southern turn and cuts through the dunes marking the edge of buttercup.
Gordon's has several very popular meeting places. Patton Valley is easy to get to from the dunes or sand highway. From the dunes just go north until you hit a big valley with lots of people. The sand highway runs along the top of the ridge that marks the end of the flats and begining of the dunes. Just follow it north until you see closure stakes and then look for the big opening in the stakes and turn east. There used to be a sign there marking the entrace but it dissapeared last summer sometime. Patton is a lot like olds only IMHO steeper and with a much friendlier crowd. The valley at the base of Patton also has a lot more vegitation than Olds valley making it much easier to find a nice shady spot to chill and watch the action on the hill.
The Gordon's equivilent of comp is test hill which is visible from I-8. IMHO test is one of the nastiest steepest hills still open at the ISDRA. Climbing it at night my lights can't illuminate the full length going up and it just seems to keep going forever. About halfway up I normally start to think I've got to be at the top only to find out I'm no where close. The easiest way to get to test is to follow a sand highway that runs on a ridge just north of the canal.
The dunes at Gordon's are outstanding! Most of the visitors stay on the first and second set of dunes so if you go just two ridges in suddenly it's virgin sand as far as you can see. Plenty of big bowls with smooth transistions between them so you can get that great roller coaster type of ride and never see another soul or track the entire time.
The far eastern edge of the dunes things get very soft though. My one friend who explored that area fairly well said one time he was just cruising along a big flat stretch of sand and suddenly his buggy sank in up to the floor boards it was so soft! So the farther east you go the more carefull you have to be. I assume there are some good dunes over there since some people camp at Ogilby and ride over there but I've yet to explore that area. Ogilby is the only ISDRA camp area I've yet to visit.
Oh, and Gordon's also has it's own version of Boardmanville/Beach store called Pair-A-Dice. It's easy to find (Just turn left instead of right when you get off the highway to enter Gordon's) has some simply outstanding grub, and a decent selection of parts along with someone who can do welding and other minor repairs. They used to even offer a tow out service but I'm told that they don't anymore.
PAD is a great place to get breakfast, nice clean bathrooms (without any extra charge to use them) delicious food and a really nice clean air condtioned dining room or a great outdoor eating area. I just wish they would stay open a little later at night as we always seem to make a beverage run around 11 but they're closed by then.
If you've never been I HIGHLY recomend checking out Gordon's or Buttercup for an "off-weekend" sometime.