The Upper Peninsula forest was more than half pine, much of it white pine, a great forest tree that grew to great size over a four-hundred-year life expectancy. Because this softwood was easily sawed with the poor saws of the time, weather resistant as lumber, and able to float, it became valuable timber. Cut in winter, it could be driven down the Escanaba and other rivers on spring flood crests to mills at their mouths. In 1851, the N. Ludington Company, owned by brothers Nelson and Harrison Ludington, bought the Escanaba River mills and enlarged them to produce 10 to 12 million board feet of pine lumber yearly. The hardwood portion of the virgin forests had to await the coming of the railroads for mass marketing because hardwoods did not float well, and some did not float at all.