The West Branch of the Susquehanna drains northern Cambria County before … [it] receives waters from the counties of Clearfield, Clinton, Cameron, Lycoming, Union, and Northumberland .

The rain, which began in the late afternoon of Thursday, May 30, continued with increased violence until Saturday, June 1. Clearfield borough had flooded streets by 5 a.m., May 31. Before daylight was far advanced, residents observed that the headwaters of the West Branch were running twelve feet deeper than ever before.

The torrents continued to pour into the river at Clearfield all day long. Renovo, southeast of Clearfield on the West Branch, was flooded by evening, May 31. By midnight, three-fourths of the town as flooded; out-buildings were floating away; the hotel was ruined; and the opera house had been demolished when a floating building struck it. Residents of Clearfield had warned Renovo and Lock Haven by telephone of the ever-rising flood.

Lock Haven lumber boom breaks

At 8 p.m., the West Branch at Lock Haven began to rise rapidly. People, fearing that the great lumber boom would break, fled from their homes. The log-dam held until 2 a.m., Saturday, June 1, when it broke with a great roar. Even after the tumbling logs had cleared the river at that point, the water continued to rise until 4 p.m., Saturday. At that peak of the flood, the water stood three feet higher than in 1865.19

Williamsport’s log boom follows

The West Branch was running seventeen feet deep at the time that the boom at Lock Haven broke. With the endless procession of the 73,000,000 feet of lumber spanning the river, the flood bore down on Williamsport where another log boom crossed the river.

The flood entered Williamsport at 3 a.m., Saturday morning. For six hours, the chains of the boom were able to hold the great mass of logs in place; then with a crackling roar, the two great burdens of logs were free; 150,000,000 feet of logs started southward to the main channel of the Susquehanna. In the wake of the logs, floated all sorts of manufacture and finished lumber products from the Williamsport mills, a railroad station, and a steady procession of barns, sheds, chicken-coops, and outhouses.

The flood at Milton threw a road bridge against a railroad trestle which fell; the two structures then destroyed a second railroad bridge. At Sunbury the West Branch unites with the Susquehanna. When the flood reached the junction city, the force of water was so great that the flood rushed up into the North Branch before its waters were accommodated by the main channel.20 …

• 19 McMaster, op. Cit., 211-214. McMaster has the best account of the flood on the Susquehanna River systems. While his manuscript in the Historical Society of Pennsylvania is devoid of citation, it is evident that he read the newspapers in the Susquehanna towns to arrive at the exact time for destruction of bridges and log-booms.
• 20Ibid., 214-215.