Image: Clymer Meadow Preserve, County Road 1140, Hunt County, Texas, USA

(go see it in person sometime!) source

The soil of the Blackland Prairies, from which the "Blackland" gets its name, contains black or dark-gray, alkaline clay in both upland and bottomland areas. "Black gumbo" and "black velvet" are local names for this soil.

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The Blackland Prairie was a disturbance maintained ecosystem prior to the arrival of Europeans. Fires ignited by lightning occasionally swept the area, clearing or reducing the encroachment of trees and shrubs on the prairie, while stimulating the native herbaceous prairie species of forbs and grasses which are pyrophytic (fire), adapted and resistant to wildfires. The exact frequency of fires is unknown but estimated to have occurred at intervals of 5 to 10 years.

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Native American hunter-gatherers contributed to the maintenance of the prairie through controlled burns to make more land suitable for hunting bison and other game. Hunter-gatherers continually inhabited the prairie since pre-Clovis times over 15,000 years ago. In historic times, they included the Wichita, Waco, Tonkawa, and Comanche, each of whom was gradually replaced by settled agrarian society. Herds of bison, and to a lesser extent pronghorn and deer, grazed on the grasses and trampled and fertilized the soil, stimulating the growth of the tall grass ecosystem. The Bison were made absent from the area by the 1850s.

The advent of large-scale irrigated farming and ranching in the area quickly led to widespread habitat loss. Although 98% of the land was cultivated around 1900 [...] as a result of cultivation, overgrazing, and other imprudent land-use practices, there are few if any remnants of climax vegetation in the region.

You can visit the following grassroots organizations for more prairies in your area.

https://texasprairie.org/

https://txmn.tamu.edu/

https://agrilifeextension.tamu.edu/