The Susquehanna Boom was a system of cribs in the West Branch Susquehanna River designed to hold timber in the river until it could be processed at one of the nearly 60 sawmills along the river between Lycoming and Loyalsock creeks in Lycoming County.
The boom was constructed in 1846 under the supervision of James H. Perkins.

A boom is a chain or line of connected floating timbers extended across a river, lake, or harbor (as to obstruct passage or catch floating objects).
The Susquehanna Boom extended 7 miles (11 km) upstream  from Duboistown to the village of Linden in Woodward Township.
The boom was constructed by creating a series of man-made islands known as "cribs".
These cribs built of local mountain stone and sunken timber were stretched diagonally across the river, beginning on the south side near Duboistown and ending on the north side near Linden.
The boom was made of 352 separate cribs that were 22 feet (7 m) high.
The boom was opened and closed at the upper end by a device known as a "sheer boom".
It was 1,000 feet (300 m) long and was controlled with a hand-powered windlass.
The sheer boom gathered the logs into the main boom that was capable of holding up to 300 million board feet (700,000 m³) of logs.
The lower end of the boom was where the logs were sorted.
The mills in Williamsport, South Williamsport, and Duboistown each had their own distinctive brand burnt into the logs.
The men working at the end of the boom would sort the logs according to their corresponding brand and float them into the correct holding pond along the bank of the river.

During the height of the lumber industry in Lycoming County, 1861–1891, the various mills produced 5.5 billion board feet (13 million m³) of lumber.
Williamsport became one of the most prosperous cities in Pennsylvania and in the United States.
Men like James H. Perkins, Peter Herdic, and Mahlon Fisher became millionaires while many of the men who actually worked in the river struggled to survive on the wages paid to them by the lumber barons.
The Susquehanna Boom was a system of cribs in the West Branch Susquehanna River designed to hold timber in the river until it could be processed at one of the nearly 60 sawmills along the river between Lycoming and Loyalsock creeks in Lycoming County. The boom was constructed in 1846 under the supervision of James H. Perkins.
A boom is a chain or line of connected floating timbers extended across a river, lake, or harbor (as to obstruct passage or catch floating objects). The Susquehanna Boom extended 7 miles (11 km) upstream  from Duboistown to the village of Linden in Woodward Township. The boom was constructed by creating a series of man-made islands known as "cribs". These cribs built of local mountain stone and sunken timber were stretched diagonally across the river, beginning on the south side near Duboistown and ending on the north side near Linden. The boom was made of 352 separate cribs that were 22 feet (7 m) high. The boom was opened and closed at the upper end by a device known as a "sheer boom". It was 1,000 feet (300 m) long and was controlled with a hand-powered windlass. The sheer boom gathered the logs into the main boom that was capable of holding up to 300 million board feet (700,000 m³) of logs. The lower end of the boom was where the logs were sorted. The mills in Williamsport, South Williamsport, and Duboistown each had their own distinctive brand burnt into the logs. The men working at the end of the boom would sort the logs according to their corresponding brand and float them into the correct holding pond along the bank of the river.
During the height of the lumber industry in Lycoming County, 1861–1891, the various mills produced 5.5 billion board feet (13 million m³) of lumber. Williamsport became one of the most prosperous cities in Pennsylvania and in the United States. Men like James H. Perkins, Peter Herdic, and Mahlon Fisher became millionaires while many of the men who actually worked in the river struggled to survive on the wages paid to them by the lumber barons.
West Branch Susquehanna River