http://breezewiki.bunny5exbgbp4sqe2h2rfq2brgrx3dhohdweonepzwfgumfyygb35wyd.onion/crosscode/wiki/Maroon_Valley
On the map below, the main path through the area is 1-2-3-4-(8/10)-9-11-14-15-17-18. All three other loops can only be unlocked in one direction (forward for the Maroon Oasis, and backward for the other two), and require completing numerous puzzles to proceed. River Cliff/Endless Pit in particular requires you to start in Barren Land and follow an upper, puzzle-filled path through Overpass to reach the areas.