That or head up HWY 16 toward Llano. When you get to Sandy Creek pull over, and pan. Powder gold up and down that creek. May or may not be water, but there is gold. Llano river upstream from Llano also has gold. Some guys dredge, some pan. Small flakes with the occasional nugget. But around Enchanted Rock? If you follow some of those streams be careful. Folks up there think they own the creeks and will shoot you. Now, I have looked into your idea since about 1963 and never found a thing. But out from Brady you can find silver and like I said, north of there(ER) you can find gold. Not much, but it is there. Get a topo and look NW of Llano(where the highest hills are). Old rumor about a deposit in there somewhere on the creeks. Never tried to look. Don't believe in rumors, but who knows...
By the way, on HWY 16, past Sandy Creek, but before you reach HWY 71, there is a dirt road going to the right. It goes back to some ranches and as you go down it there is a deposit of very heavy white crystalline rock. Was told it was lead and silver ore. I have a fairly large piece sitting here, but I never followed up on that either. You may want to take a look. Have fun, good luck and if the old rock shop is open on the square in Llano, they can tell you what has been found and where. Just be polite. Been a long time since I've been up that way...