Jeffrey Anderson is describing this location on his website dwarve´s earth treasures.

“...I know of Stillwater Ranch south of Marathon along route 385, but I haven't visited that ranch. I picked up info that the access to the agate source in Stillwater Ranch somewhat became more restricted, so it may not worth about 100 miles of driving from Alplne, Texas to get there ... I was actually surprised to get one with amethyst core in one of them and other with strong shadowing effect....”