Remnants left behind, Ranch History at Big Bend Ranch State Park

Two stock tanks--one round, one rectangular--out on
remote ranch land in Big Bend Ranch State Park...which is
older, do you suppose?

If you look closely, the wildlands of Big Bend Ranch State Park reveal relics of its ranching past.  Consider these two stock tanks side by side--one is round, the other rectangular--which do you suppose is older?

The round stock tank was made of stone, and it is believed manual laborers gathered local stone to construct the tanks.

Our TPWD guide, Blaine Hall, believes the rectangular one was the more recent addition--as the shape indicates a form was used to form the concrete stock tank.

Water was pumped from Sauceda to remote areas of the park, and you can see remnants of that enterprise, if you look closely!