The West Branch Susquehanna River reflects the history of lumbering in Pennsylvania, from the first small-scale seasonal sawmills of the 1780s, which supplied local needs and sent wood downstream on lumber rafts, to the sawmills of the 1830s that used logs or "sticks" floated downriver in rafts or scattered drives captured by booms across the river, with the straightest stock used as masts or "spars" for shipbuilding in the Chesapeake Bay. From 1864 to 1941, logging railroads became the principal means of hauling timber, especially hemlock for leather tanning and lumber, and their efficiency helped bring Pennsylvania's forests to near-clearance by the 1930s. The resulting erosion increased sediment in the West Branch and downstream to the Chesapeake Bay, leading the PA Bureau of Forestry, the U.S. Forest Service, and the Civilian Conservation Corps to play major roles in controlling wildfires, erosion, and forest depletion while restoring and protecting the state's forests. After World War II, new hardwood forests replaced the white pine and hemlock forests, and sustainable forestry practices emerged, keeping land in forest use, supporting cleaner rivers and more wildlife, and helping make Pennsylvania the nation's leading producer of hardwoods while more than half the state remains forested.