Pennsalt Historic District

Natrona is an unincorporated community in Harrison Township, Allegheny County in the U.S. state of Pennsylvania. It is located in western Pennsylvania within the Pittsburgh Metropolitan Statistical Area, approximately 24 miles (39 km) northeast of Downtown Pittsburgh. Natrona is situated along the Allegheny River at Lock and Dam Four, Pools Three and Four between Brackenridge, Natrona Heights, Karns, Allegheny Township, and Lower Burrell.

The Allegheny River Lock and Dam No. 4 in Harrison Township, Allegheny County, Pennsylvania, is a lock that was built 1920-1927, and opened in 1927, 24.2 miles upstream from the mouth of the river in Pittsburgh. The lock and dam were built by the U.S. Army Corps of Engineers as a part of an extensive system of locks and dams to improve navigation along the Allegheny River. It is located about 24.2 Miles up the Allegheny River from the Point in Downtown Pittsburgh. Also, it is about 6 Miles down the Allegheny from the mouth of the Kiskiminetas River.Upriver, Allegheny Pool No. 4 has an average water elevation of 745.4 feet above sea level and extends about 6.2 miles upriver to Allegheny River Lock and Dam No. 5. Downriver, Allegheny Pool No. 3 has an average water elevation of 734.5 feet above sea level and extends about 9.7 miles downriver to Allegheny River Lock and Dam No. 3. Thus Lock No. 4 lifts and lowers boats about 10.9 feet between the pools.It has a single lock and a fixed-crest dam, keeping the river depth at least 9 feet in the pool above the dam. The amount of water that flows over the dam is not controlled locally, so it does not provide flood control, but it does help provide water to municipalities.Traffic through the lock was about 1.8 million tons in 1998, including shipments of coal, petroleum, sand and gravel, ore, steel, chemicals, fertilizer, salt, flour, lime, and slag.It was listed on the National Register of Historic Places on April 21, 2000.

Highlands High School is a suburban, public secondary school in the Natrona Heights neighborhood of Harrison Township in the U.S. state of Pennsylvania. It is part of the Highlands School District and has a current enrollment of about 800 students in grades nine through twelve.

Saint Joseph High School is a private, parochial Roman Catholic high school in Harrison Township, Pennsylvania. It is the only parish-operated high school in the Diocese of Pittsburgh.

Chartiers Run is a tributary of the Allegheny River located in Westmoreland County in the U.S. state of Pennsylvania. It was named after Peter Chartier, a trapper of French and Native American parentage who established a trading post at the mouth of Chartiers Creek in 1743.

Jacks Island is an alluvial island in the Allegheny River. Its southwestern half lies in the city of Lower Burrell, while its northeastern half lies in Allegheny Township, in Westmoreland County in the U.S. state of Pennsylvania. The island is situated across from Harrison Township in Allegheny County.The elevation of Jacks Island is 745 feet above sea level.

Natrona Heights is an unincorporated community in Harrison Township, Allegheny County in the U.S. state of Pennsylvania. It is located in Western Pennsylvania within the Pittsburgh Metropolitan Statistical Area, approximately 24 miles (39 km) northeast of Pittsburgh. Natrona Heights is situated near the Allegheny River, Natrona, Brackenridge, and Tarentum.

Harrison Township is a township in Allegheny County in the U.S. state of Pennsylvania. The population was 10,169 at the 2020 census. Pennsylvania Route 28 passes through Harrison Township, connecting Kittanning to the northeast and Pittsburgh to the southwest. Allegheny Technologies has extensive steel mill facilities in Harrison Township, including its Allegheny Ludlum Brackenridge Works. Harrison Township is located at the far northeast corner of Allegheny County. Its northern border is the Butler County line and the Allegheny River forms the township's eastern boundary with Westmoreland County. Its northeast corner also touches Armstrong County.

Brackenridge Works is a specialty steel mill facility owned by Allegheny Technologies and operated by its Flat-Rolled Products segment in the Pittsburgh suburbs of Natrona, Pennsylvania.

The Burtner House (also known as the Burtner Stone House) is an historic home which is located on Burtner Road in Harrison Township, Allegheny County, Pennsylvania in the United States. It was added to the National Register of Historic Places in 1972.

Brackenridge is a borough in Allegheny County, Pennsylvania, United States, located along the Allegheny River. It is part of the Greater Pittsburgh metropolitan area. The town is named for Henry Marie Brackenridge. The borough once had glass factories. An Allegheny Technologies steel mill, Allegheny Ludlum Brackenridge Works, plays a prominent role in the community, although most of the facility is located in Harrison Township. The borough's population stood at 3,421 in 1910 and at 6,400 in 1940. As of the 2020 census, it was 3,240.

Karns is an unincorporated community in Harrison Township, Allegheny County, Pennsylvania, United States; it is located in Western Pennsylvania within the Pittsburgh Metropolitan Statistical Area, approximately 24 miles (39 km) northeast of Pittsburgh. Karns is situated along the Allegheny River at Pool 4 across from Jacks Island just above Lock and Dam 4 between Natrona, Natrona Heights, and Sligo. The elevation of Karns is 817 feet above sea level.The postal ZIP code is 15065, while the telephone area codes are 724 and 878; although the code 878 is not used.