Saw Mill Run
|Saw Mill Run|
|Origin||Castle Shannon, Pennsylvania|
|Length||9.3 mi (15.0 km)|
|Basin area||19 sq mi (49 km2)|
Saw Mill Run is a tributary of the Ohio River in Pennsylvania. It is an urban stream, and lies entirely within Allegheny County, Pennsylvania. The stream enters the Ohio just downstream from the Forks of the Ohio in Pittsburgh, at a place originally founded as the town of Temperanceville in the 1830s. It provides an entry through the elevated plateau south of Pittsburgh known as the South Hills, and land transportation has paralleled the stream since the nineteenth century.
The Coal Hill Coal Railroad crossed the stream on a trestle, and extended upstream in 1861. This railroad was purchased by the Pittsburgh and Castle Shannon Railroad, who extended the line to follow the main stream of Saw Mill Run from the Pittsburgh and Castle Shannon Tunnel to Castle Shannon, Pennsylvania. The Little Saw Mill Run Railroad followed the west branch of the stream towards Mt. Lebanon, Pennsylvania.
Trolley and light rail
The right of way of the Pittsburgh and Castle Shannon, excluding the tunnel through a coal mine, was leased by Pittsburgh Railways in 1905, and later purchased in 1950. The railroad ran with a dual gauge system, with coal trains continuing to run on the narrow gauge, and at night, and trolleys on a wider gauge. The right of way is part of the Pittsburgh Light Rail transportation system today, which follows the stream from near the South Hills Junction (PAT station) to Castle Shannon, Pennsylvania.
Part of Pennsylvania Route 51 runs parallel to the stream, and this section is known as Saw Mill Run Boulevard.
The watershed of Saw Mill Run covers 12, 432 acres (1.75 km2), or about 19 square miles (49 km2). The main stream is 9.3 miles (15.0 km) long, and drains parts of Bethel Park, Castle Shannon, Mount Oliver, and the city of Pittsburgh.
- Annual Report of the Geologic Survey of Pennsylvania for 1885-1887. p. 161.
- "AMD and Sediment MDLs for Sawmill Run" (PDF). Retrieved 2009-05-24.[dead link]