However, he changed his mind, and after a trip back East returned and, on a site noticed by the owner on his visit, built a grist mill on a small stream now called Washington's Run that empties into the Youghiogheny.

This was one of the first mills erected west of the Alleghany Mountains and is still standing, though more or less rebuilt.

The millstones were dug out of quarries in the neighborhood and the work of building the mill was done amid considerable danger from the Indians, who had begun what is known as Dunmore's War.

Simpson's cabin and the slave quarters stood near what is now Plant No.

2 of the Washington Coal and Coke Company.
The tract of land contains valuable seams of coal and with some contiguous territory is valued at upward of twenty million dollars.
Washington had large ideas for the development of these western lands.
At one time he considered attempting to import Palatine Germans to settle there, but after careful investigation decided that the plan was impracticable.