Turkey Creek Nature Preserve is one of the few public outdoor areas in the metro area where you can walk across the boundary of two Level III Ecoregions. Turkey Creek flows out of the Level III: Ridge and Valley │ Level IV: Southern Limestone/Dolomite Valleys and Low Rolling Hills (take a breath…) into the Level III: Southwestern Appalachians │ Level IV: Shale Hills just as it curves at Bull Frog Bend (also called Blue Hole). At this sharp bend in the creek, evidence of changing terrain can be seen by the steep canyon walls and twisted creek bed. A walk from the Preserve entrance gate to The Falls takes you from one Ecoregion to the next.
A small eastern portion of The Preserve is within the Southern Limestone/Dolomite Valleys and Low Rolling Hills level IV Ecoregion. The terrain of this Ecoregion is one of karst topography interrupted occasionally by hills of chert and sandstone. The limestone/dolomite valleys produce springs such as Tapawingo Springs and other smaller springs that feed Turkey Creek. Most of the Preserve lies within The Shale Hills, a part of the Southern Appalachians, covers over 2000 square miles including the Warrior Coal Field where much of the coal for the steel industry was mined.
Original forest for both Ecoregions contained Oak-Hickory or Oak-Hickory-Pine. The limestone/dolomite valleys also supported oak bottomland forests.