BLM maps are more like charts that show an anchorage. You should camp where others have camped before rather than forge a new spot. The best way to show someone the anchorage is to have them google map the location and get the satellite view of the area. Remember the ant farms and how the tunnels looked in between the walls? that view will be presented in the satellite view, believe me. Most 14 day camping locations are like in the nfs free 14 day locations, about 2 miles from any fee areas.
We just landed at the imperial dam LTVA BLM camp area This area and other LTVA areas are nothing more than large natural parking lots. No designated spots to camp at only the 15 foot rule.