I tried many ways to climb the mountain, and so far I had success with this path:

1. Collect the first 3 pill normally, in the order of the Any% run.

2. Move forward to the rocks, and climb them until you get to a rocky "hill" near a vertical wall (0:28), this is the highest rocky platform in the nearby area

3. From there, jump over the wall to a small platform on the top

4. Move to the right, and position yourself near the white trail (from the outside) (1:18)

5. Jump across the white trail, until you reach the top.

The jump across the first and second walls are not easy to do, but hopefully with some practice and tries they won't be the worst thing ever.