There are numerous lagoons in the Llano districts caused by the periodical floods of the rivers, and extensive esteros and cienagas, in part due to the same causes, but these either dry up in the dry season or are greatly reduced in area.
A very thin soil covers the Edwards Plateau, but on the Llano Estacado are brownish and reddish loams derived from the sediments of a Neocene lake.
Texas Spur - Held in the spring and fall, this Llano, Texas-based Jamboree involved some very rocky terrain.
boundary of New Mexico the Great Plains province is known as the Edwards Plateau; between the Edwards Plateau and the valley of the Canadian river, as the Llano Estacado, or Staked Plains; and N.
On the Llano Estacado there are both freshwater and salt lakes, and there are a few salt lakes in the Trans-Pecos Province and near the mouth of the Rio Grande on the Coastal Plain.