We tried a new camping spot this weekend. We went past Lucky Peak, past Arrowrock Dam, past all the boat launches, and up to road 377. You pass a ranger station and get to a Cotoonwood trailhead. The trail is actually a very pleasant hike, though it is a lot of uphill and it was hot, so I sort of got tired of it sooner than I would have liked. If you hike awhile you get to a bridge though, and the dogs can play in the river, get a drink, and cool off. There are also some shady rest spots.
Just past the trailhead is a nice picnic spot next to the river. It is very near the road so I wouldn't recommend it for camping, but it has been used as such. We drove further down the road to find camping. There are not a lot of spots since there has been forest fire recently in this area. We reached the summit and turned left, headed towards Thorn Creek. We eventually found a very nice campsite, secluded, with flat spots, a fire pit, and even firewood and some water for the dogs to play in.
On the way home we thought we'd try continuing on the road, as it shows on the map a connection to Highway 21. Don't do this. The road is completely washed out and unless you have 4WD, great clearance, guts, and a willingness to tackle driving on the rocks in the river for a period of time and taking a MAJOR downhill, you can't make it. We did tackle some very, very tricky technical spots and one river crossing in the Subaru Outback. We punctured a tire though, couldn't make the wash out anyway, and had to turn back. There were no road closed signs and nothing on the map.