In the simplest terms, to be wild. To go to the mountain, or take it to the mountain, means to act as if you lived in the mountains. Some people take this literally to act like cavemen, others only as far as lumberjacks. Can be incorporated with getting back to nature.
It originated with a boys' cross country team camping in the woods. They got lost on their run and one of them had to use a toilet. Because they were out in the open and didn't want to smell it while they were sleeping later, the team told him to take it to the mountain (pointing uphill to the top of the mountain they were on). So he did.
Real men don't camp in RVs, light campfires with matches, or use toilet paper. Real men go to the mountain.
It originated from the idea of the old-fashioned above-ground outhouses that stunk up a mile radius. Signs on the doors would instruct the users to scoop some sawdust, provided in the stall, into the tank to prevent odors from permeating.
Can also be phrased "add a scoop"
Dude, where you going? We're about to jump in the lake!
Just a second guys, I'm gonna add a scoop of wood.