The lower Santa Fe group was created by dune fields and small streams draining into playa lakes and mud flats.
13.
The area topology is gently rolling plains with a large number of playa lakes on top of a large plateau.
14.
However, the presence of gypsum does not necessarily require large surface water bodies ( e . g ., playa lakes ).
15.
The lakes are part of what are called playa lake chains, and the system is often referred to as an example
16.
The slopes of playa lakes in the Texas Panhandle and surrounding regions are used as habitat for the black-tailed prairie dog.
17.
Due to the lack of developed drainage, much of the rainfall either evaporates, infiltrates into the ground, or accumulates in playa lakes.
18.
Soil types vary from dark brown playa lake silt to iron rich clay to sandy soil; topsoil and subsoil layers vary as well.
19.
Some regulations included water features such as intermittent streams, playa lakes, prairie potholes, sloughs and wetlands as " waters of the United States ".
20.
Ten percent of the land is covered with Playa lakes ( shallow lakes which hold rainwater part of the year ) are commonly found.
