Question: Where is the water the Brilliant Branch Railroad Bridge crosses?

full_context: Document 1: Brilliant Branch Railroad Bridge: The Brilliant Branch Railroad Bridge is a truss bridge that carries Allegheny Valley Railroad's Brilliant Branch across the Allegheny River between the Pittsburgh neighborhood of Highland Park and Aspinwall, Pennsylvania.
Document 2: Allegheny River: The Allegheny River (/ ˌæləˈɡeɪni / AL - ə - GAY - nee) is a principal tributary of the Ohio River; it is located in the Eastern United States. The Allegheny River joins with the Monongahela River to form the Ohio River at the ``Point ''of Point State Park in Downtown Pittsburgh, Pennsylvania. The Allegheny River is, by volume, the main headstream of the Ohio River.
Document 3: Herr's Island Railroad Bridge: The Herr's Island Railroad Bridge, also known as the West Penn Railroad Bridge, is a truss bridge across the Allegheny River between the Pittsburgh neighborhoods of Troy Hill and Herrs Island (commonly referred to as Washington's Landing).
Document 4: Cowanshannock Creek: Cowanshannock Creek (the eastern section is sometimes referred to as the North Branch Cowanshannock Creek) is a tributary of the Allegheny River in Armstrong and Indiana counties, Pennsylvania in the United States.
Document 5: Highland Park Bridge (1902): The 1902 Highland Park Bridge was a cantilever through truss that carried two streetcar tracks across the Allegheny River and Sixmile Island between the Pittsburgh neighborhood of Highland Park and Sharpsburg, Pennsylvania. It was replaced by the Highland Park Bridge in 1938.
Document 6: Freeport Rail Bridge: The Freeport Rail Bridge is a truss bridge that carries the Norfolk Southern Railway across the Allegheny River between Freeport and Allegheny Township in Pennsylvania.
Document 7: Pucketa Creek: Pucketa Creek is a tributary of the Allegheny River located in both Allegheny and Westmoreland counties in the U.S. state of Pennsylvania.
Document 8: 33rd Street Railroad Bridge: The 33rd Street Railroad Bridge is a truss bridge that carries the Allegheny Valley Railroad on the P&W Subdivision over the Allegheny River in downtown Pittsburgh, Pennsylvania, United States.
Document 9: French Creek (Allegheny River tributary): French Creek (also known as the Venango River) is a tributary of the Allegheny River in northwestern Pennsylvania and western New York in the United States.
Document 10: Deer Creek (Allegheny River tributary): Deer Creek is a tributary of the Allegheny River located in both Allegheny and Butler counties in the U.S. state of Pennsylvania.
Document 11: Homestead Grays Bridge: The Homestead Grays Bridge, also known as the (Homestead) High Level Bridge, was built in 1936 and spans the Monongahela River between Homestead Borough and the southernmost tip of Pittsburgh's Squirrel Hill neighborhood. It is notable as the first bridge to incorporate the Wichert Truss, which uses a quadrilateral shape over each support, into its design. This made the truss statically determinate, so that forces in the structural members could be calculated.
Document 12: Parker Bridge: Parker Bridge is a truss bridge in the city of Parker, Pennsylvania in the United States. The bridge, constructed in 1934, carries motor vehicles and pedestrians over the Allegheny River.
Document 13: List of crossings of the Monongahela River: This is a complete list of current bridges and other crossings of the Monongahela River starting from Pittsburgh, Pennsylvania, where the river helps to form the headwaters of the Ohio River, and ending in Fairmont, West Virginia, where the West Fork River and Tygart Valley River combine to form the Monongahela.
Document 14: PC&Y Railroad Bridge: The PC&Y Railroad Bridge carries a single railroad track over the Ohio River, between Stowe Township, Allegheny County, Pennsylvania and Neville Island, Pennsylvania.
Document 15: Cheat River: The Cheat River is a tributary of the Monongahela River in eastern West Virginia and southwestern Pennsylvania in the United States. Via the Ohio River, the Cheat and Monongahela are part of the Mississippi River watershed. Owing to the ruggedness of the surrounding Allegheny Mountains, the Cheat remains largely remote with few settlements or developments along its banks. Its headwaters are in the Cheat-Potomac Ranger District of the Monongahela National Forest.
ground_truth: Eastern United States
sub_queries: What does Brilliant Branch Railroad Bridge cross over? Answer: Allegheny River
where is Allegheny River located on a map Answer: Eastern United States