Nature areas have been divided into four categories
- National Nature Areas - Any U. S. Government operated nature area, including National Preserves, Wildlife Refuges and Forest.
- State Nature Areas - Includes State Parks, Natural Areas and Historic Sites
- Wildlife Management Area - Operated by the state.
- Miscellaneous Nature Areas - All other Nature Areas including City, County and Privately operated areas.
- Great Texas Wildlife Trail - Information about The Great Texas Wildlife Trails with links to on and off site pages.