This is the Beaver Mill after the flood!

Beaver Mill is now located in Black Moshannon State Park - Timber!:  Towering white pines and hemlocks once covered the surrounding slopes and the dense foliage blocked out the sun, making it dark even on sunny days.  Weathered stumps now mark where the Beaver Mill Lumber Company cut these trees about a century ago.  Some beaver ponds disappeared when loggers constructed a splash dam near the site of the present dam.  The water from the splash dam was used to flush logs downstream.  Eventually, the logs floated down the Susquehanna River to mills in Williamsport.  In one year, the Beaver Mill Lumber Company floated over 11 million feet of logs, the largest amount put in by any single logger in Pennsylvania.  Some wood was processed at a shingle mill, located below the present beach. 
     By 1879, timber was cut at the steam-powered Star Mill, once located at the north end of Star Mill Trail.  The mill boasted 20 saws, a planer and a shingle mill.  It was supported by 150 teams of horses and mules and a second village called Beaver Mills located near Shirk's Run at the south end of the park.  When Star Mill operated, the dam was changed again, to a mill pond to store logs     Before the turn of the 20th century, Beaver Mills and Antes featured a large general store, a wagon shop, a blacksmith shop, mills, stables, a hotel-tavern, a schoolhouse and a 10-pin alley!  The schoolhouse still stands near the food concession.  The rugged people of the area helped meet the nation's growing need for timber for mining, railroads and construction.  Some thought the timber supply would never end.
     It did end, almost.  As the supply of timber decreased, lumber companies moved.  The denuded landscape lumbermen left behind fell prey to fires and erosion.  The job market collapsed. maps here

 PA Lumber MuseumWIKI entry  / Johnstown Flood memoirHERE / Flood article NY Times 

Susquehanna Boom

The Susquehanna Boom Company was incorporated onMarch 26,1846.^[6] There were initially 100 shares of stock issued at $100 per share. The firstshareholders were John Dubois (founder of Duboistown and laterDubois, Pennsylvania) and his brother Matthias DuBois, each with 25 shares, Perkins had 24 shares, Isaac Smith had 20 shares, Elias S. Lowe (a partner of the DuBois brothers) had five shares, and Leighton had one share, perhaps as payment for services. John DuBois was elected President of the Boom and served in that capacity until 1857.^[2]