It's surprising what a vast amount of stuff there is in Joshua Tree. Much of it is hidden away on the network of trails; a gigantic concentration of mines and tunnels that I haven't seen anywhere else. Joshua Tree has a ton more mines than Death Valley, concentrated into a much smaller area; specifically the New Dale mining district immediately north of the park on BLM land.
The features are organized into folders that include highways (in yellow), unpaved trails (in red), abandoned structures (green houses), photos (pink camera icon), and waypoints (red pushpins).
Download the Joshua Tree file here