Ancient Cross Timbers Project:  http://www.uark.edu/misc/xtimber/  The Cross Timbers are the post oak and blackjack oak woodlands that form the western frontier of deciduous forests in Texas, Oklahoma, and southeastern Kansas. Literally thousands of acres of ancient forest survive in the Cross Timbers because these stout oaks were too short and craggy for commercial sawlog production.   Post oak trees up to 400 years old and red cedar trees over 500 years old have been found in these interesting woodlands. Unfortunately, the great antiquity of the uncut Cross Timbers is not widely appreciated and they continue to be destroyed.  This project is dedicated to the location and appreciation of these authentic ancient forest remnants. 

Oklahoma's Forests Oklahoma Department of Agriculture, Food & Forestry: Oklahoma's Forests http://www.oda.state.ok.us/forestry-okforestshome.htm 

World Wildlife Organization - Ozark Mountain Forests (NA0412) 
http://www.worldwildlife.org/wildworld/profiles/terrestrial/na/na0412_full.html  
Cucumber Creek Watershed (72.85 km2). The Oklahoma Nature Conservancy owns 6.07 km2 of this watershed, which includes some large shortleaf pine on the steeper slopes that are 51 to 76 cm in diameter and blackgum and hickory that may be up to 91 cm in diameter. Large sycamore trees occur along the stream. The upper part of the watershed has probably not been cut since the turn of the century. 

Characterization of an Old-Growth Forest in the Cross Timbers of Oklahoma, Clark, S.L.; Hallgren, S.W., 2004. Gen. Tech. Rep. SRS-73. Asheville, NC: U.S. Department of Agriculture, Forest Service, Southern Research Station. pp. 160. Many cross timbers forests in central Oklahoma were neither extensively logged nor farmed and may contain some of the largest tracts of old-growth forests, particularly those dominated by oak, in eastern North America (Therrell and Stahle 1998). We studied a 90 ha old-growth forest in Osage County, Oklahoma which is one of the few designated forest preserves in the cross timbers. Our objectives were (1) to examine changes in species composition and structure across a topo-edaphic gradient and (2) to determine how well these stands conform to traditional models of old-growth stand structure.  http://www.srs.fs.usda.gov/pubs/gtr/gtr_srs004.pdf  14 kb.

Oklahoma Nature Conservancy - Cucumber Creek Nature Preserve http://www.kotv.com/okt/natureconservancy.asp  The 3,236-acre preserve is one of the most pristine and biologically diverse sites in the Ouachitas. Sixteen state rare plants and four endemic plants have been documented from the preserve Forested slopes and bottomlands provide critical habitat for numerous neo tropical migrant bird species. The creek supports a thriving population of the rare Ouachita Mountain shiner and a dozen other fish species. Also see: http://nature.org/wherewework/northamerica/states/oklahoma/preserves/cucumber.html 

GORP - Oklahoma Wilderness Areas http://gorp.away.com/gorp/resource/us_wilderness_area/ok.htm Black Fork Mountain, Charons Garden, North Mountain, Upper Kianichi River.