Ecoregions of Texas

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° 37 28 37° COLORADO 39 21 KANSAS Ecoregions denoteOKLAHOMA areas of general similarity in ecosystems and in the type, quality, and quantity of environmental resources. They 25 are designed to serve as a spatial framework for the research, assessment, management, and monitoring of ecosystems and ecosystem 40 components. These general purpose regions are critical for structuring and implementing ecosystem management strategies across C 26 im federal agencies, state agencies, and nongovernment organizations that are responsible for different types of resourcesMISSOURI within the a rr same geographical areas 21 on The approach used to compile this map is based on the premise that ecological regions can be identified through the analysis of the Ri 26a ve 39 25b spatialr patterns of biotic and abiotic phenomena, including geology, physiography, vegetation, climate, soils, land use, wildlife, and Tulsa 36° hydrology. The relative importance of each characteristic varies from one ecological region to another regardless of the hierarchical 36° 25e 26a 26a level. The Ecoregions of Texas map was compiled at a scale of 1:250,000. Compilation of this map was part38 of a collaborative project 25b r ve primarily between the TCEQ, US EPA, USGS, USDA-NRCS, as well as with other state and federal agencies. Comments regarding Santa Fe Ri this map should be addressed to Glenn Griffith, Dynamac Corp., c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, (541) 754- 4465, [email protected]; Sandy Bryce, Dynamac Corp., c/o US EPA, 200 SW 35th Street, Corvallis, OR 97333, s(541)a 754- C Lake Canad an s 26 anad ia Oklahoma City Ark 26d ian Meredith 27 4788, [email protected];n or Jim Omernik, U.S. Geological Survey, 200 SW 35th Street, Corvallis, OR 97333, (541) 754-4458, R 23 27h [email protected] Fort Smith i ver Albuquerque 29 37 Amarillo Citation: Norman 35° Griffith, G.E., S.A. Bryce, J.M. Omernik, J.A. Comstock, A.C. Rogers, B. Harrison, S.L. Hatch, and D. Bezanson, 2004, Ecoregions 35° 26a 26c of Texas, U.S. Environmental Protection Agency, Corvallis, OR. 23 37 27h PRINCIPAL AUTHORS: Glenn E. Griffith (Dynamac Corporation), Sandra A. Bryce (Dynamac Corporation), James M. Omernik 22 (USGS), Jeffrey A. Comstock (Indus Corporation), Anne C. Rogers (TCEQ), Bill Harrison (TCEQ), Stephen L. Hatch (Texas A&MHot Springs 25i 26b LawtonUniversity), and David Bezanson (Natural Area Preservation Association). 36 23 Clovis 26b Red 34° 25j 27h Ri 34° ver 35 23 Lake 35g 26b Texoma 35c Wichita 33 River 35c 35g a Falls 29b 35a 35 26b i t Lake 35c 33d Wich Arrowhead Paris 33d 35c NEW MEXICO Lubbock Sherman Roswell 26c R 35c Bra 27i lphur i 35a Texarkana z Su ve o r 25 s 32a 25j R i Denton Lewisville 33d 33f 35b ve 35c 33° 24 r Lake 33d ARKANSAS 33° 23 33d LOUISIANA 25j 26b 26b 29d 33f 35a 24 Dallas Lake 29f 32c Tawakoni 35b 27h Fort 35a 35b Shreveport Worth Arlington 33a Longview 26b Las Cruces Carlsbad Sabine Tyler Abilene R Cedar iv Pa 29b 35b e Big Spring lu Creek r R xy e 29c Res. d 32° 24c River ° 30d 35a R 32 iv Midland er El Paso 23b Guadalupe Mtns. Odessa 27j 23a P L 33f Ciudad Juarez National Park ec eon T 35 24a os ri R ni Nacogdoches Brownwood iv ty C e o r R l Waco i 24b 24a or B v Toledo Bend 24d 25k a r e Laguna de 24a R San Angelo do a r ive 25j R z 35b Sam Rayburn Reservoir Pecos r iv 29e o Guzmán er s 32c N Res. R a Lufkin i 35e CHIHUAHUA24c v v 33b 24e e a ° r s 35b 31 o Neches 31° 30d t R 24d 24d 24e Temple a io

r R S

e 35e 35b a

Fort Stockton iv i 33f b

San S R 33b v aba Lake i

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24b 35b R n r 24c e Livingston i

Llano v 33c R

Bryan 35b e 24d r i

er v v e Ri 35f 24d 30b r 30a no 32a G 24e Lla Lake Big Thicket 35b r 33c a 24d 33b 32b Conroe National Preserve n 24b 35f d River 35b 35f e 32c Lake Charles les Austin 24b Pederna 33b 34a 30° 24d 30° 24d 32c 32b 33f Beaumont P Kerrville 33e e C 34a 23 Arizona/New Mexico Mountains c ol 34 o Gu o adalup rado 32c 23a Chihuahuan Desert Slopes 24d 24c 24a s e 33b 34a R 33f Houston 24b i 34g 23b Montane Woodlands v 30c R 33f e iv COAHUILA r er 34g Galveston 24 Chihuahuan Deserts Bay R 24a Chihuahuan Basins and Playas 24c 24d iver 32b 34h San 34a 24b Chihuahuan Desert Grasslands Amistad 31b Antonio 33b Galveston Reservoir Del Rio 24c Low Mountains and Bajadas 24c Ciudad Acuña Uvalde 31a 29° 24d Chihuahuan Montane Woodlands ° 24d Big Bend 34a 29 24e Stockton Plateau 24b National Park S 34c 31d an 34c 25 High Plains UNITED STATES An 34a ton Victoria 25b Rolling Sand Plains io 34h R i 34a 25e Canadian/Cimarron High Plains MEXICO ve 34c F r ay 25i Llano Estacado r M a B io atagord 32 Texas Blackland Prairies er 25j Shinnery Sands R iv 34h 25k Arid Llano Estacado 32a Northern Blackland Prairie 31c iver R 32b Southern Blackland Prairie s 34b ° e 28 26 Southwestern Tablelands c 28° 32c Floodplains and Low Terraces N ue 26a Canadian/Cimarron Breaks 34h 34c 34h 26b Flat Tablelands and Valleys 33 East Central Texas Plains 34h 33a Northern Post Oak Savanna R 26c Caprock Canyons, Badlands, and Breaks i 33b Southern Post Oak Savanna o Corpus Christi 26d Semiarid Canadian Breaks 31d 33c San Antonio Prairie 34b 27 Central Great Plains Laredo 33d Northern Prairie Outliers 27h Red Prairie Nuevo Laredo Kingsville Padre Island 33e Bastrop Lost Pines 34i National Seashore GULF OF MEXICO 27i Broken Red Plains 33f Floodplains and Low Terraces 34i 27° 27j Limestone Plains 27° 34 Western Gulf Coastal Plain 29 Cross Timbers 34a Northern Humid Gulf Coastal Prairies

29b Eastern Cross Timbers 34d

e 34b Southern Subhumid Gulf Coastal Prairies r

29c Western Cross Timbers d 34c Floodplains and Low Terraces a

29d Grand Prairie Falcon M 34d Coastal Sand Plain a

29e Limestone Cut Plain Reservoir n u 34e Lower Rio Grande Valley g

29f Carbonate Cross Timbers 34e a G L 34f Lower Rio Grande Alluvial Floodplain rande 30 Edwards Plateau 34g Texas-Louisiana Coastal Marshes 31d McAllen 26° 30a Edwards Plateau Woodland 34h Mid-Coast Barrier Islands and Coastal Marshes 34i 26° 30b Llano Uplift 34i Laguna Madre Barrier Islands and Coastal Marshes Reynosa 34f 30c Balcones Canyonlands SCALE 1:2 500 000 35 South Central Plains Brownsville 30d Semiarid Edwards Plateau 35a Tertiary Uplands Level III ecoregion Matamoros 3020 10 0 60 120 mi 31 Southern Texas Plains 35b Floodplains and Low Terraces Level IV ecoregion 31a Northern Nueces Alluvial Plains 35c Pleistocene Fluvial Terraces County boundary 60 40 20 0 120 240 km 31b Semiarid Edwards Bajada 35e Southern Tertiary Uplands State boundary

e

International boundary r 31c Texas-Tamaulipan Thornscrub 35f Flatwoods d Albers equal area projection a

25° 31d Rio Grande Floodplain and Terraces 35g Red River Bottomlands M Standard parallels 27û 30' N and 34û 30' N 25° a NUEVO LEON n u TAMAULIPAS g a L

° 106° 105° 104° 103° 102° 101° 100° 99° 98° 97° 96° 95° INTERIORÑGEOLOGICAL SURVEY, RESTON, VIRGINIAÑ2004 107 94°