No charge at King Rd. It's just standard BLM land like all over the west, not one of the longer term visitor areas. Free with a 14 day limit. No services, just open land. There are several BLM long term visitor areas nearby. Those have various charges, with the main ones being $40 for two weeks, or $180 for up to 7 months. The main ones are near Quartzsite and north of Yuma near Imperial Dam. In all, I've stayed about 4 months in that area.