During those busy spring days when the Joshua Tree National Park is swirling with tourists, backpackers and rock climbers, you may want to consider spending the day in the Black Rock Camp area. To reach it from L.A. while driving on Highway 62, do not go as far as the main Tourist Center and Park entrance; instead turn right when in Yucca Valley and follow the sighs for the Camp. You will not need to purchase a Park pass to go there.
Park your car in front of the Black Rock Visitor Center and spend some time exploring it. It is the only place in the whole Park where you can buy some memorabilia (fridge magnets, backpack patches, etc) and postcard to send home, it has a water fountain to fill your bottles, and very helpful rangers that will give you all the information you may need to explore the area.
The map that the rangers provide is unfortunately not super detailed but their explanations are clear and the trails are very well indicated. If you feel full of energy and want to fill the day with a good 15-20 km hike, we suggest going for Warren Peak and Panorama Loop trail as we did. The West Side Loop trail and the Short Loop are easier hikes.