Unami Creek/Ridge Valley Creek Conservation Landscape
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CHAPTER 3 Unami Creek/Ridge Valley Creek Conservation Landscape The central feature of the Unami Creek/Ridge Valley Creek Conservation Landscape is a large block of unbroken forest bordering the Unami and Ridge Valley Creeks and covering the ridge that separates the two streams. This landscape is an important source area for birds and helps to maintain bird diversity elsewhere in the county. It is also supports six state listed species of plants and an extremely scenic landscape centered around the boulder-strewn Unami Creek. Description Location The Unami Creek/Ridge Valley Creek Conservation Landscape occupies a broad swath of land extending northeast from the mouth of the Unami Creek to the Bucks County boundary (Figure 3.1). Containing 9,196 acres, it includes parts of Marlborough, Salford, and Upper Salford Townships. The valleys of the Unami and Ridge Valley Creeks and the diabase ridge that separates them are the major landscape features. The landscape adjoins the Spring Moun- tain, Mill Hill/Deep Creek, and Upper Perkiomen Creek/Green Lane Reservoir Conservation Landscapes to the west The Unami Creek in the Musser Scout Reservation (Figure 3.1). The Unami Creek/Ridge Valley Creek Conservation Landscape is part of the larger 16,000-acre Unami Forest, which extends into Bucks County. Geology The landscape of the Unami and Ridge Valley Creek valleys is shaped by the broad zones of the Boyertown diabase sheet that encircle Red Hill, Green Lane, and Pennsburg and extend into Bucks and Lehigh Counties. Weathered, exposed diabase is responsible for the boulder- choked course of the Unami Creek and the ringing rocks boulder fi eld along Ridge Valley Creek. The northwestern one-third of the Unami/Ridge Valley Creek Conservation Landscape includes a second, narrower diabase dike and an area underlain by Brunswick Formation shales and sandstones (Figure 3.2). The landscape includes an active quarry located on the north side of the Unami Creek near its Natural Areas Inventory Update 2007 63 confl uence with the Perkiomen Creek where metamorphosed shale known as hornfels, is being extracted and crushed for use in road building. Forest Cover Overall the area remains 67 percent forested, due to the unsuitability of the rugged, rocky hills for agriculture (Figure 3.3). It is one of few forested tracts of this size remaining in southeastern Pennsylvania, exceeded in size only by the Hopewell Big Woods area that straddles the Berks/ Chester County boundary. An important characteristic is the presence of 3,738 acres of forest interior. The large blocks of unbroken forest and extensive areas of riparian forest habitat along the creeks constitute prime bird habitat. Hydrology The landscape includes the Unami and Ridge Valley Creeks from the Bucks County border to their mouths. It also includes the lower portion of the Macoby Creek, a tributary that enters the Perkiomen Creek at Green Lane. The Unami Creek basin in Montgomery County (which in- cludes Ridge Valley Creek), is designated HQ-TSF (high quality, trout stocked fi shery). The Ma- coby Creek designation is TSF (trout stocked fi shery). The Unami Creek is dammed at two locations within the landscape, form- ing Lake Delmont and Long Lake in the Musser Scout Reservation. In addition the remains of a mill dam can still be seen closer to Sumneytown. Ridge Valley Creek is dammed to form Whites Mill Pond. Skymount Lake, another impoundment, is locat- ed on an unnamed tributary of Ridge Valley Creek. Stone arch bridge and early mill on the Unami Creek above Sumneytown The National Wetlands Inventory lists only 18.1 acres of wetlands within the landscape; most within the fl oodplains of the Unami and Ridge Valley Creeks or associated with the lakes at Camp Skymount and Whites Mill. Critical Features Extensive areas of interior forest habitat are the most important feature of this landscape. In ad- dition, three high priority sites identifi ed in the 1995 Natural Areas Inventory are included: Ridge Valley Site, Whites Mill Meadow, and Whites Mill Swamp (Figure 3.4). Plant Diversity – The presence of six PNHP-listed plant species was confi rmed during 2006- 2007: prairie phlox, Indian paintbrush, showy goldenrod, pinelands pimpernel, Mead’s sedge, and goldenseal. 64 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 65 66 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 67 68 Natural Areas Inventory Update 2007 Natural Areas Inventory Update 2007 69 Birds – One hundred and seventy-six (176) species of birds have been recorded in the Unami Creek Valley throughout the year in habitats ranging from interior forest, riparian forest, fl ood- plains, and grasslands to emergent wetlands and ponds. At least 30 species of concern have been noted (Table 3.1). Table 3.1 — Bird Species of Conservation Concern in the Unami Creek Valley Important Bird Area (from Stell 2006) Nesting Habitat Status Veery breeding forest interior Ovenbird breeding forest interior American Redstart breeding forest interior Scarlet Tanager breeding forest interior PIF regional responsibility Blue-gray Gnatcatcher breeding forest interior Black-and-white Warbler breeding forest interior Hooded Warbler breeding forest interior G5/S2S3B/CR Audubon Cerulean Warbler breeding riparian forest watch list (extirpated) Acadian Flycatcher breeding riparian forest PIF regional responsibility Audubon watch list, USFS Kentucky Warbler breeding riparian forest species of concern Worm-eating Warbler breeding riparian forest Audubon watch list Louisiana Waterthrush breeding riparian forest USFS species of concern Forest understory/ Wood Thrush breeding USFS species of concern ground Understory of mixed Swainson’s Thrush migrant, rare breeder S2/S3B/S5N CR forests Bay-breasted Warbler neotropical migrant USFS Region 5 Forest understory/ Canada Warbler neotropical migrant USFS Region 5, national ground Eastern screech owl breeding Deciduous woods PIF regional concern Forest understory/ Eastern Towhee breeding PIF regional concern ground Chimneys in residential Chinmey Swift breeding PIF regional concern structures Forest understory/ PIF continental concern/re- American Woodcock breeding ground gional responsibility USFS Region 5, national; Olive-sided Flycatcher fall migrant Riparian forest SXB PX G5 Great Blue Heron breeding (rookery present) Wooded swamps S3/S4B/S4N G5 Green Heron breeding Swampy thickets PIF wetland priority Little Blue Heron breeding? Riparian forest USFS national Prairie Warbler breeding Open woods, fi elds USFS Region 5, national Golden-winged Warbler breeding? Successional/thicket USFS Region 5, national Forest understory/ PIF piedmont concern; Northern Bobwhite breeding ground SZ/S3 CA PS American Black Duck breeding Riparian forest PIF piedmont concern 70 Natural Areas Inventory Update 2007 Blue-winged Warbler breeding Successional/thicket PIF piedmont concern Field Sparrow breeding PIF piedmont concern Greater Scaup migrant PIF piedmont concern Canvasback migrant PIF piedmont concern Redhead duck PIF piedmont concern PIF piedmont concern; S2B Osprey breeding Forested wetlands PT PT Green-winged Teal breeding S1/S2B/S3N CR Black-crowned Night Heron breeding? Wetlands and streams S2/S3B CA Northern Saw-whet Owl breeding? Coniferous woodlands S3B/S3N CU Great Egret breeding? Forested wetlands S1B PE PIF=Partners in Flight, USFS=United States Fish and Wildlife Service, G=global rank, S=state rank, C=candidate, PE=Pennsylvania endangered, PT=Pennsylvania threatened. Past Uses Bean’s History of Montgomery County Land assessments for Marlborough Township in the 1800s distinguished between usable land and “rock land,” which was taxed at a lower rate. The streams powered gristmills, saw mills, fulling mills, (linseed) oil mills and (gun and blasting) powder mills. The forested hills were the source of timber for building material, fuel, and char- coal making. Charcoal was hauled to Green Lane to power the iron forge that was operated there from about 1733 until 1812 by the Maybury family and later by William Schall. Charcoal was also an ingredient in the manufacture of gun powder, a local industry that was centered in the vicinity of Sumneytown during the 1800s (see box 3.1). Box 3.1 — Powder Mills in the Unami Creek Valley In 1865 there were 11 mills in Marlborough Township, most along the Unami Creek, producing 20 tons of powder daily. The production of powder involved mixing saltpeter and sulfur obtained from Philadel- phia with locally produced charcoal. Accidental explosions were not uncommon, usually caused when the mixture was not kept adequately moist during mixing or if a spark occurred during milling. Because of the danger, powder mills were usually located in thinly populated areas. Powder from the Unami Creek Valley supplied troops during the Civil War and was also shipped north on the Schuylkill Canal to the coal region for use in mining. It seems likely that it was also used in local quarrying of diabase to produce Belgian blocks for building and road construction. Evidence of quarrying, in the form of drill holes and split surfaces, is readily apparent on the wooded slopes along the Unami Creek. Protection Status and Other Designations The 1,250-acre Musser Scout Reservation is protected under a conservation easement held by the Natural Lands Trust. In addition, an agreement has recently been reached to protect the 150-acre Diversifi ed Community Services Camp located along the Unami Creek between Camp Hart and Camp Delmont. The Natural Lands Trust also owns the 150-acre Fulshaw Craeg Preserve and holds easements on 1,368.5 acres in the Ridge Valley Creek/Unami Creek area (Figure 3.5). Publicly owned land includes 145.1 acres owned by Marlborough Township and 144.7 acres owned by Salford Township. Natural Areas Inventory Update 2007 71 The Unami Hills area of Montgomery and Bucks Counties has been designated as one of the criti- cal treasures of the Pennsylvania portion of the Highlands Region by the Highlands Coalition. The Coalition Webpage describes the area as: The Unami Hills region of northern Montgomery County is part of a diabase rock for- mation that stretches across Bucks and Montgomery Counties.