The carvings, are well hidden, perfectly placed stones, in certain placement order, same distance patterns. They didn't want it to be lost forever, for it to lost forever would be a catastrophe, and would avail nothing. Yea, it took a large work forces, probably servants, slaves, got done, killed them. To procure a guide and two or three servants would be beneficial, hereafter, is what one of the Beale letters stated, so you know they were using them. Every time they completed a project, only a few would, return. Keep everyone fresh, and in check, don't want to be those guys, the ones left behind. You want to Ride to the end, got to prove it, tough back then, sure they had a process, of Picking associates, prob, use lodges, pure investigated