Background The first covered bridge in the United States was built in 1800 over the
Schuylkill River in
Philadelphia, Pennsylvania. According to Susan M. Zacher, author of
The Covered Bridges of Pennsylvania: A Guide, the first covered bridges of the Burr arch truss design were also built in the state. Pennsylvania is estimated to have once had at least 1,500 covered bridges and is believed to have had the most in the country between 1830 and 1875. In 2001, Pennsylvania had more surviving historic covered bridges than any other state; 221 remained in 40 of its 67 counties. Covered bridges were a transition between stone and metal bridges, the latter made of cast-iron or steel. In 19th-century Pennsylvania, lumber was an abundant resource for bridge construction,
Construction and description All three Sullivan County covered bridges were built c. 1850 with Burr arch trusses. The Forksville and Hillsgrove bridges both cross Loyalsock Creek, with the latter about 5 miles (8 km) further downstream. On July 2, 1973, the Hillsgrove bridge was the first covered bridge in Sullivan County to be added to the NRHP, and on July 24, 1980 it was again included on the NRHP in a
Multiple Property Submission of seven
Covered Bridges of Bradford, Sullivan and Lycoming Counties. The covered bridge rests on
abutments of stone and mortar, which have been reinforced with concrete. There are no parapets. The bridge deck is made of crosswise "narrow width laid flooring".
Use and restoration In the 19th century the Hillsgrove Covered Bridge survived major floods on March 1, 1865, and June 1, 1889, that destroyed other bridges in the West Branch Susquehanna River valley. Between about 1870 and 1890, logging in the Loyalsock Creek watershed produced lumber rafts that floated beneath the bridge. The bridge was the site of "Uncle Ben's Landing" for lumber rafts, which did not travel at night. These rafts, each containing 5,000–30,000
board feet (11.8–70.8 m³) of lumber, were carried down the Loyalsock to its mouth at
Montoursville. The raft era ended when the
eastern hemlock were all
clearcut. An April, 1963 article on covered bridges in Sullivan and Lycoming counties noted that the Hillsgrove Bridge's deck was "a bit swaybacked", The concrete reinforcement on the southwest abutment of the Hillsgrove bridge is dated 1968, but the other work done in this restoration is not documented. Lewis also restored the Forksville Covered Bridge in 1970, with what its NRHP nomination form describes as "all kinds of odd repairs". Lewis' restoration work at Forksville involved cutting windows into the sides of the bridge for the first time, with four windows on the south side and three on the north. Covered Bridge Road north of Loyalsock Creek is accessed only by the Hillsgrove Covered Bridge at the eastern end, and a bridge over Elk Creek at the western end. Sullivan County replaced the bridge over Elk Creek between March 21 and July 21, 1989. Without the Elk Creek bridge, access for five families, a business, and a
Little League Baseball camp with 110 children was limited to the covered bridge. County officials noted that despite the covered bridge's posted weight limit of , it could still support , sufficient for small fire trucks and ambulances. In an emergency, larger emergency vehicles could
ford the creek if needed. In any case, the limited access did not cause any problems for the four-month period while the Elk Creek bridge was replaced. The Evans' book describes repairs to the bridge's northeast siding, done between 1991 and 2000. In 2010, the bridge was rehabilitated for the first time since the 1960s. Sullivan County solicited bids in February, expecting the project to cost between $200,000 and $500,000. The metal roof was replaced with cedar shake shingles, repairs were made to the wooden structure, portals, and siding, the bridge and deck were cleaned, and the bridge was painted red. The rehabilitation cost $150,516, and the bridge reopened in the autumn of 2010. In 2011, the bridge was badly damaged by historic flooding from
Hurricane Irene in late August and
Tropical Storm Lee in early September. Sullivan County applied for and received
Federal Emergency Management Agency funding for repairs to both bridges. The Hillsgrove bridge was restored first, as it was the main route to a restaurant and heavily used by hunters. Repairs included replacement of broken structural beams, sections of the deck, and siding. Because Loyalsock Creek is an "Exceptional Value Stream", the scaffolding that supported the structure on the creek bed during the $250,000-restoration had to be approved by the
Pennsylvania Department of Environmental Protection. The bridge was reopened on November 21, 2012, just in time for deer hunting season, by one of the Sullivan
County Commissioners; the county commissioner had been married on the bridge exactly 25 years before. Despite the 2010 restoration, the 2012
Federal Highway Administration National Bridge Inventory found the bridge to be "Structurally Deficient". According to Zacher, the "Sullivan County bridges, because of their settings, are some of the most attractive in the state". ==Bridge dimensions==