Caption: Logging in Pennsylvania peaked in the latter half of the 19th century. Basic hand tools were used to fell immense trees.

Caption: Completed in 1851, the Williamsport Log Boom, by holding hundreds of thousands of logs until needed by local sawmills, enabled Williamsport to become the "Lumber Capital of the World" in the late 1800s. At its peak, the Boom's six miles of walls could hold close to a million logs in a 450-acre enclosure. The boom remained in place until 1909, when its dismantling ended the water era of sawmilling in Williamsport.

Caption: Where the terrain was too rough or remote for the rails, horses and mules dragged, or "skidded" the logs out.

Caption: Hemlock trees were stripped for their bark, which at the time was the primary source for tannin, used in leather processing. Shown here, a group of loggers stripping bark from a downed tree.

Caption: The Pennsylvania timber industry was a foraging operation in which lumberjacks left mountain sides strewn with debris. In the early 1900s forest fires that roared through the dead stumps, dry branches, scrub brush, and saplings devastated some 350,000 acres each year as rains clogged streams with eroding soils and fed devastating floods. The logs in this photo, however, were drying rather than abandoned. Dried hemlocks were lighter, less slippery, and easier to floated downstream to river-side sawmills.

Caption: Logs arrive by train to the sawmill at Laquin, Pennsylvania, in 1880. The town of Laquin, like others in the state, sprung up around the logging industry. By 1941, the big trees were long gone and the town was abandoned.