That rubble pile has a destroyed president buried in it.
Jefferson originally sat on Washington's right. Workers spent 18 months carving him before Borglum discovered the granite there was too cracked to hold a face. In 1934 he ordered the entire head dynamited off the mountain. The debris landed on the slope below, where it still sits.
The rest of the pile tells you how the monument was actually made. Dynamite did 90% of the carving. One pound of explosive removed one cubic yard of rock, and by 1941 the crew had blasted 450,000 tons off the mountainside. Borglum always planned to haul it away. Congress cut the funding, work stopped in October 1941, and the pile stayed.
Here's the twist: cleaning it up is now illegal. The National Park Service classifies the talus slope as a cultural resource, protected the same way as the faces themselves. Pocket a single rock and you've committed a federal crime.
So the "mess" will outlast everyone complaining about it. Black Hills granite erodes about one inch every 10,000 years. That pile, with a blasted Jefferson somewhere inside it, sits on a longer timeline than the country whose presidents it came from.
Mount Rushmore is disgusting. They couldn't be bothered to clean up their mess.