The Slocum Creek campground is near the Owyhee Reservoir at the end of Leslie Gulch. It is a free campsite, fire rings with shelters (!) and tables. There are two drop toilets but no water or trash service. Closest gas is in Jordan Valley. The boat ramp to the reservoir is a half mile down the hill. The reservoir is very still and great for SUP and kayaking as well. The area is accessed by a good dirt road, but since it is in a gulch, a small amount of water could make this area tricky to drive to/from, so be sure to watch the weather. There are other camping spots in the Owyhee, but this is the most accessible with the best maintained road. Fires were allowed in late June, but I suspect there is a fire ban throughout July/August/September. 

First come first served. Websites mentioned that it almost never fills up except maybe during fishing season, but we arrived on a Friday in June and the campground did run out of spots by early evening. There are dispersed spots nearby, but then you would need to plan to bring a portable toilet and your own shelter. The sun was sweltering, even in June. 

There is great hiking (requires some scrambling) in the smaller gulches off Leslie Gulch with incredible views of the rock formations. Juniper Gulch is a moderate, somewhat shaded, and stunningly beautiful hike nearby. 

Rattlesnakes, ticks, and scorpions live in this area. 

There is one larger group site, but it gets the last of the evening sun and the first of the morning sun. 

These lands are fragile, so please take care of them: pack out your garbage, stay on trails, only ride dirt bikes and four wheelers on the roads.