I think the easiest way to find the path is like this:
Go to Neltharion's Lair on the map. It's clearly marked and pretty easy to see how to get there. Personally, I took the eastern path out of Thunder Totem and followed the river south, ignoring the rest of the roads, but that's just me.
Just to the west of the dungeon enterance is a small bridge over the river that connects to a path going southwest. This path leads to the aforementioned Summitcrest Basecamp. As murfl said, the path up the mountain begins at 48, 69. It's completely covered in snow, and there's a goat.
The path up to the summit is pretty easy to follow, but there is one point where it forks near the top (52, 84), and the path you need to take doesn't look too much like a path at all. Watch for the trail markers (the posts with ropes on them), and if you start going down instead of up, you took the wrong path.
Edit: Apparently, I didn't know what a compass was.