The sabkha is a wetland region where groundwater rises and falls seasonally, leaving white alkali deposits on the surface Inland saltgrass is common in this area. Toads can reproduce in sabkha wetlands when they are seasonally filled with sufficient fresh water. Shore birds such as the American avocet hunt tadpoles and insects in the shallow water. The sabkha is at approximately 7500' (2286m) in elevation.

The sabkha forms where sand is seasonally saturated by rising groundwater. When the water evaporates away in late summer, minerals similar to baking soda cement sand grains together into a hard, white crust. Areas of sabkha can be found throughout western portions of the sand sheet, wherever the water table meets the surface. Some wetlands in the sabkha are deeper with plentiful plants and animals, while others are shallow and salty.

Sabkha deposits can accumulate into thick crusts.  Early settlers collected sabkha minerals to use in baking or laundry detergent.  In the 19th century, a tiny town appeared nearby called Soda City. Residents collected and pressed the minerals into blocks that were shipped by train to be sold as washing soda.  Few traces are left of the town today.

Credits and Sources:

“Great Sand Dunes: Natural Features and Ecosystems,” http://www.nps.gov/grsa/learn/nature/naturalfeaturesandecosystems.htm, Accessed June 28, 2015.

“Great Sand Dunes System,” National Park Service, http://www.nps.gov/grsa/learn/nature/sand_system.htm, Accessed on June 28, 2015.