An intensive botanical survey of the Thurmond Ranch in southern Roger Mills County, Oklahoma was performed in the spring, summer, and early fall of 2001. Field work was conducted by personnel of the Kansas Biological Survey and the R.L. McGregor Herbarium of the University of Kansas, and the Oklahoma Biological Survey of the University of Oklahoma. The purpose of the project was to document and collect the floral species growing along the Ogallala ecotone, as an adjunct to ongoing, long-term archeological and paleoclimatological research in the Dempsey Divide study area (Bement 2000; Bement and Buehler 1994, 1998; Buehler 1997; Thurmond 1990, 1991a, 1991b, 1991c, 1997; Thurmond and Picarella 1999; Thurmond, Wyckoff, and Batchelor, 1998; Thurmond and Wyckoff 1998, 1999, 2001).

     The place name "Dempsey Divide" was coined by Thurmond (1990) for the uplands between the Washita and North Fork of the Red rivers in western Oklahoma. The other major interfluvial divides of northwestern Oklahoma have been subsequently named (Thurmond and Wyckoff 1999). Lead botanists on the botanical survey were Craig Freeman, an authority on Great Plains plant systematics and taxonomy (c.f. Collins et al. 1995; Freeman 1998a, 1998b, 2002; Freeman and Schofield 1991; Freeman et al. 1997, 1998); and Kelly Kindscher and Hillary Loring, specialists in Great Plains ecology and ethnobotany (Kindscher 1987, 1992, 1995; Kindscher et al. 1996, 1998; Lauver et al. 1999; Loring et al. 1999, 2000). As a result of this survey, the Thurmond Ranch was listed on The Oklahoma State Register of Natural Heritage Areas, administered by the Oklahoma Biological Survey, in September of 2001 (Shannon 2001, 2002).

    A total of 487 taxa have been recorded as of 12/01/2001.  The collections and identifications have been made by Craig Freeman and Caleb Morse of the University of Kansas, R.L. McGregor Herbarium; Kelly Kindscher and Hillary Loring of the University of Kansas, Kansas Biological Survey; and Bruce Hoagland and Amy Buthod of the University of Oklahoma, Oklahoma Biological Survey. 

    Most of the amphibian and reptilian species were identified during a survey of the Thurmond Ranch by Sam Noble Oklahoma Museum of Natural History biologists Laurie Vitt and Janalee Caldwell in August of 1996. The remainder of the species on this list have been identified by Pete and Susie Thurmond since 1992.

1) Species List of Modern Local Fauna

2) Species List of Modern Local Flora

3) Ethnobotany of the Dempsey Divide (Thurmond et al.2002)

4) Vascular flora of the Ogalla Ecotone (Freeman, Morse & Thurmond, in press)