To get to the second treasure map of the Ash Heap region, I fast travelled from my camp to the exterior of The Rusty Pick. It's a free fast travel point I'm guessing because, well, it's a heap of ash populated by molerats, mole miners, and the local merchant mumbles so badly, no one is really sure how to say his name. From there I travelled southwest past a large generator, a square concrete building, and a lakeside cabin, until the second lakeside cabin was a few paces away on my left. Then I searched the ground for the telltale mound of uniform, gray rubble that marks the treasure site. Once I dig and score a suitable stash of loot, I'm overencumbered and cannot fast travel. So I follow the railroad tracks heading North-Northwest from the Pick until I get to the Charleston Fire Department vendor, where I can sell said loot for a backpack full of caps. Rinse and repeat, until Vendor Bot Mack is dry.
Ash Heap Map 02 — The Burning Claim