* [http://www.nps.gov/gumo/naturescience/geologicformations.htm Permian Reefs in Guadalupe Mountains National Park, Texas, USA] Much of this park was donated to the country by Wallace Pratt, one of the founders of AAPG. | * [http://www.nps.gov/gumo/naturescience/geologicformations.htm Permian Reefs in Guadalupe Mountains National Park, Texas, USA] Much of this park was donated to the country by Wallace Pratt, one of the founders of AAPG. |