After plundering Map #3, I went after Cranberry Bog Treasure Map #4. The nearest fast travel point was Pylon V-13. After some searching, I found it at the northern end of the Bog. The Pip-Boy map icon reminded me of a gondola or electric train car suspended in a circle. I found the needed icon between the Abandoned Bog Town to the west and the Old Mold Quarry to the east. The Pylon is right next to train tracks. Once I arrived there, I traveled directly to the base of Pylon V-13 and stood so my view was oriented north-northeast. Using the line of pylons as a guide, I headed toward the second pylon, went past it, and continued on to the third pylon.
And that's where I found the treasure mound, right at the base of that third pylon. Specifically, it was on the side of the structure that faces back toward the first pylon. The mound was of brown mud with grass around it and a couple of nondescript mushrooms to its left. That's all there was to it—I scavenged a ton, as it was decent loot. Then I crawled, overburdened, to Watoga where I could sell off what I didn't need. One thing I should note: if you fast travel to the V-13 Pylon, you will definitely run into some Scorched, possibly some Slasher Kids, and maybe a Scorchbeast or three. If you follow my directions and die, don't worry, I'll save your loot bag… promise!