Camping around Spearfish

I'm headed up to Spearfish this weekend with some friends, and I wanted to get a sense for what camping options exist in the surrounding area. I know there's the campground near Hanna, but it's the fourth and I'd like to have a backup that doesn't involve scrounging late at night or camping somewhere we shouldn't, etc. Access for our user group is important and I'd like to play by the rules. Currently my plan is to leave CO Friday morning and try to lock down some space at the Hanna campground, but I'm assuming there will be a lot of others given the holiday weekend.

For those who have some experience in Spearfish, how would you approach this? Any thoughts on the surrounding area that would help us keep a low profile?

when we went a few years ago we were able to find small pullouts on some of the random dirt roads in the general area.  that being said, they were small (it was just us sleeping in the truck, so not too big a deal), and they were not very close to the climbing.  the hanna campground is small and fills up quickly, so my guess is that it will be packed on the 4th.

how big is your group?  that will likely be the major factor.

Thanks Slim- Most of my friends who have been have also done the truck-in-pullout camping, which seems ideal if you're with one partner. We are not terribly large, 6 - 8 ppl, but it's still more than enough to narrow the options. I'm also not married to the idea of camping right near the canyon- I have no problem driving a bit out of the way to find some space or to avoid camping illegally, but it doesn't sound like there are lots of readily available options. 

Another good option is to get a private pay campground in Spearfish or Deadwood.  They are a little more but offer walking distance to the brewery and, restaurants for instance.  Also most of them have pools and hot showers.  There are a few decent free spots by hanna.  

My girlfriend and I have been in Spearfish for 5 days. Finding free camping was a trick but we found a nice meadow about a half mile after hanna on the left that was perfect. You could definitely fit a small group there easily. We had it to ourselves almost every night but definitely let others join when they needed. Fire danger is very high right now so I would suggest no fire. Another option is drive up road 222 at savoy. go left through private property staying on road 222. (it is legal to drive this road just stay on the road) After 1.5 miles you will enter National Forest Service Land and you can basically drive up a short dirt road and be in Wyoming where camping legally is no issue. Good luck. Spearfish Is RAD! Prepare yourself for the pump! 

Fires are illegal outside of established campgrounds I believe.  No nee for it in the middle of the summer.