The ecoregion is mountainous, forested, and underlain by Pennsylvaniansandstone, shale, and siltstone. It is one of the Ozark Plateaus; some folding and faulting has occurred but, in general, strata are much less deformed than in the Ouachita Mountains. Maximum elevations are higher, soils have a warmer temperature regime, and carbonate rocks are much less extensive than in the Ozark Highlands. Physiography is distinct from the Arkansas Valley. Upland soils are mostly Ultisols that developed under oak-hickory and oak-hickory-pine forests. Today, forests are still widespread; northern red oak, southern red oak, white oak, and hickories usually dominate the uplands, but shortleaf pine grows on drier, south- and west-facing slopes underlain by sandstone. Pastureland or hayland occur on nearly level ridgetops, benches, and valley floors. Population density is low; recreation, logging, and livestock farming are the primary land uses. Water quality in streams is generally exceptional; biochemical, nutrient, and mineral water quality parameter concentrations all tend to be very low. Fish communities are mostly composed of sensitive species; a diverse, often darter-dominated community occurs along with nearly equal proportions of minnows and sunfishes. During low flows, streams usually run clear but, during high flow conditions, turbidity in the Boston Mountains tends to be greater than in the Ouachitas. Summer flow in many small streams is limited or non-existent but isolated, enduring pools may occur.[2]
Geology and physiography
Boston Range spanning northwestern Arkansas and northeast Oklahoma
The area is underlain by Pennsylvanian sandstone, shale, and siltstone, where some folding and faulting has occurred.[5] The sandstone beds become thinner with higher shale content in the west as the mountains decline in elevation.[6]
The Boston Mountains form the southwestern part of the Ozark plateau where they are the highest portion of the Ozarks. Summits can reach elevations of just over 2,560 feet (780 m) with valleys 500 feet (150 m) to 1,550 feet (470 m) deep. Wahzhazhe Summit (formerly known as Buffalo Lookout), is the highest point in the Ozarks at 2,561 feet (781 m), and is located in the Boston Mountains, 3.4 miles (5.5 km) east of Pettigrew, Newton County, Arkansas, at N35.8637°, W093.4931°. Wahzhazhe is the Osage people’s name for themselves in the Dhegiha Siouan language. Turner Ward Knob (TWK) is the second highest named peak, 2.2 miles (3.5 km) east of Wahzhazhe Summit. Located in western Newton County, Arkansas, its elevation is 2,463 feet (751 m). Nearby, four other unnamed peaks have elevations at or slightly above 2,560 feet (780 m).[8] The other three highest peaks are located 4–5 miles (6.4–8.0 km) south-southwest of Turner Ward Knob along Arkansas Highway 16.[8][9][10]
^ This article incorporates public domain material from Woods, A.J., Omernik, J.M., Butler, D.R., Ford, J.G., Henley, J.E., Hoagland, B.W., Arndt, D.S., and Moran, B.C. Ecoregions of Oklahoma(PDF). United States Geological Survey. Retrieved January 18, 2018.{{citation}}: CS1 maint: multiple names: authors list (link) (color poster with map, descriptive text, summary tables, and photographs).
^[NAD83 geographic coordinates for TWK are N35.8631°, W093.4544°. Coordinates for the four unnamed highest peaks are N35.8607°, W093.4935°; N35.8151°, W093.4968°; N35.8126°, W093.4984°; and N35.7990°, W093.5005°]
