Region
Texas
2,636
United States
227
New Mexico
131
Houston
65
Mexico
65
Oklahoma
62
Edwards Aquifer (Tex.)
60
Louisiana
60
Mexico, Gulf of
53
San Antonio
46
El Paso
34
Austin
31
Edwards Aquifer
30
Bexar County
25
Big Bend National Park
25
Black Kettle National Grassland (Okla. and Tex.)
25
Rita Blanca National Grassland (Okla. and Tex.)
25
Big Bend National Park (Tex.)
23
Dallas
22
Gulf Region
22
Galveston Bay
21
Trinity River Watershed
21
Guadalupe Mountains National Park (Tex.)
20
California
19
Kiowa National Grassland
19
McClellan Creek National Grassland
19
Colorado
18
Gulf Coast
18
Southwest, New
18
Arkansas
17
West (U.S.)
17
El Paso County
16
Fort Worth
16
Mexican-American Border Region
16
Houston Region
15
San Antonio Region
15
Trinity Aquifer (Tex.)
15
Waco
15
Guadalupe Mountains National Park
14
San Antonio Missions National Historical Park (San Antonio, Tex.)
14
San Antonio River Watershed
14
Texas, West
14
Montana
13
Rio Grande (Colo.-Mexico and Tex.)
13
Uvalde County
13
Arizona
12
Balcones Canyonlands National Wildlife Refuge
12
Balcones Canyonlands National Wildlife Refuge (Tex.)
12
Big Thicket National Preserve (Tex.)
12
Alaska
11
more ...