The following is for anyone who does not know what the qualifying standards for caves vs. rock shelters in the state of Texas (each state differs). This standard is set by the Texas Speleological Survey. A karst feature (potential cave) must be at least 5 meters (about 17 feet)or greater in length. The length can be horizontal, vertical, or a combination thereof. This does not qualify if the width exceeds the length, thus a rock shelter that has an entrance width of say 100 feet, but length (front to back) is only 50', remains classified as a rock shelter, and not an actual cave. A rock shelter 50' wide, but 100' in length may be classified as an actual cave. In review, I found these statistics intresting an thought I'd share them. Texas indians used both caves and rock shelters (mostly rock shelters). Caves with sharp vertical entrances were generally not inhabited, however, many were used for unorthodox style burials. I have found points in small vertical sinkholes while atempting to open new caves. All this evidences is that ground mammals inhabited them, and occasionally, it was a good place for the hungry indian to nab a meal.