Clarksville, Pennsylvania

South Fork Tenmile Creek is a 32.10 mi (51.66 km) long 5th order tributary to Tenmile Creek in Greene County, Pennsylvania.

Castile Run is a small tributary to South Fork Tenmile Creek in southwestern Pennsylvania. The stream rises in northeastern Greene County and flows southeast entering South Fork Tenmile Creek at Chartiers, Pennsylvania. The watershed is roughly 25% agricultural, 69% forested and the rest is other uses.

Morgan Township is a township that is located in Greene County, Pennsylvania, United States. The population was 2,341 at the time of the 2020 census.

The John Rex Farm, also known as the Goodwin/Strickler Farm, is an historic American home and farm that are located in Jefferson Township in Greene County, Pennsylvania. It was listed on the National Register of Historic Places in 1998.

Plum Run is a 5.37 mi (8.64 km) long 2nd order tributary to Tenmile Creek in Washington County, Pennsylvania.

Colver-Rogers Farmstead, also known as the Norval P. Rogers building, is a historic building located at Morgan Township in Greene County, Pennsylvania. The original section was built in 1830, and is a two-story, stone dwelling, with a two-story stone wing, in a vernacular Greek Revival-style. The building was modified about 1906, with the addition of a gambrel roof and rambling porch with Colonial Revival-style design elements. Also on the property is a bank barn (c. 1880) and large wash house (c. 1906).It was listed on the National Register of Historic Places in 2003.

The Horn or Horn Davis or Overholtzer Bridge was a historic wooden covered bridge located in Morgan Township in Greene County and West Bethlehem Township in Washington County, Pennsylvania. The bridge collapsed in March 1994, and has not been replaced or rebuilt.

Hughes House is a historic home located at Jefferson Township in Greene County, Pennsylvania. It was built in 1814, and is a 2+1⁄2-story, three-bay, banked stone dwelling. It has a small, 1+1⁄2-story extension and a steeply pitched gable roof.It was listed on the National Register of Historic Places in 1972.

Deemston is a borough in Washington County, Pennsylvania, United States and part of the Pittsburgh metropolitan area since 1950. The population was 751 at the 2020 census.

Lake Monongahela was a proglacial lake in western Pennsylvania, West Virginia, and Ohio. It formed during the Pre-Illinoian ice epoch when the retreat of the ice sheet northwards blocked the drainage of these valleys to the north. The lake formed south of the ice front continued to rise until it was able to breach a low divide near New Martinsville, West Virginia. The overflow was the beginning of the process which created the modern Ohio River valley.

Jefferson is a borough in Greene County, Pennsylvania, United States. The population was 253 at the 2020 census, a decline from the figure of 270 tabulated in 2010. The borough was named after Thomas Jefferson.

Tenmile Creek is a stream in Washington and Greene Counties, Pennsylvania, USA. It is a tributary of the Monongahela River.