An excellent DV dayhike is Corkscrew. It's near the Nevada border. There are several GPS tracks on the net, and you'd definitely want one, along with software for your phone. (My current favorite is Avenza. I start with CalTopo, unload a track into that software, then print a map in .pdf format. Email the map to yourself, and presto - you have a great nav app that works outside cell phone service.) The trailhead is a way place on the hwy. It's important that you follow the track to the right wash - there are alot of them, and if you just try any of them chances are you'll find a dead end/ridiculously steep vertical wall. Once you gain a bit of elevation, there's a faint trac, with a few cairns. If your group is quiet you may be rewarded by spotting some desert big horns (they're a different than the mountain big horns).

It's a great hike, and a marvelous way to see a bit of the park others might not. Pay attention on the way down once you leave the wash and enter the playa.