Red Rock is a rock formation in south-central Wyoming that was used by travelers on the Overland Trail to record signature inscriptions from passersby. The wind-smoothed red rock stands about 20 feet high and has a circumference of about 120 feet. The sandstone formation records signatures dating to at least the 1850s. The signatures on the upwin…Red Rock is a rock formation in south-central Wyoming that was used by travelers on the Overland Trail to record signature inscriptions from passersby. The wind-smoothed red rock stands about 20 feet high and has a circumference of about 120 feet. The sandstone formation records signatures dating to at least the 1850s. The signatures on the upwind side of the rock have weathered to faint traces. The rock is on privately owned land.