Just an FYI, prospecting in the San Gabriels is illegal. The designation of the monument doesn't change that.
Hunting is currently allowed in many National Monuments. I really think you are confusing National Monuments with National Parks. Hunting is also allowed in wilderness areas unless they are in National Parks. Again, I think you are confusing National Monuments with National Parks.
As for sidewalks, are they there now? Getting National Monument status may actually improve the chances of there being accessible facilities in the future.
If you want to blame a president on the current use of Monument status, make it Teddy Roosevelt in 1906.
And Jimmy Carter designated 56 million acres (not 50,000).
