Called a "dugout".
There are still some on west Texas ranches. 6666, Pitchfork, Wagoner (former), JA, and probably some only a handful of new land owners know about.
I hunted a SW Texas ranch owned by a friend. One year, I found myself at the fringes of the 20 sections. It would have involved crossing a fence, and I did not know if the fence was boundary or cross. So I did not close the distance. 400 yards ahead was a structure built out of cross ties. Two ties long, one deep, and 6' tall. To this day, it is a 5 mile ride to water. Chihuahuan desert mountains lay 20 miles to the SW, in Mexico. Back at the house that night, I told the land owner what I saw, and asked if it was a Lion's shack. Yes it is. One cowboy would stay back there by himself, and would be resupplied once a month. This went well into the time of mechanization. At least into the 1960's as I recall him saying.