Today the area has a great diversity of features. On the east, land rises to over 1100 feet and on the west to over 1200. In both places there are precipitous bluffs rising 350 to 400 feet above the river. These highlands are deeply penetrated by numerous streams, which form deep gullies with steeply sloping banks, leaving relatively little of the original plateau or flat land on top. Parallel to the river, is the flat flood plain some 1500 feet wide. Beyond this, the ground rises sharply to the 900 foot contour where it again flattens out on the former flood plain, most of which lies within Harmar and Springdale Townships. Beyond this are the steep slopes of the upper levels, which almost completely encircle the area. The one exception is the broad, low valley of Deer Creek running to the Expressway before coming down the hill to Creighton. The river originally flowed north towards the Great Lakes but its path was blocked during one of the Ice Ages, so it turned south.

    Centuries after the river finally settled into its present location, the first Native American settlers moved into the area. The Allegewi or Allegheny Indians were probably the first. It was for them the Allegheny River and Allegheny County were named.

    The Indian town in Springdale was called Sewickley Old Town by the first white people, and must have been an important one as it is shown on a map made for William Penn in 1774 as having seven tents. A 'tent' on a map represented a certain number of people. The river makes a great bend at Springdale and the Native American settlement of Sewickley Old Town sat on what is now the present site of the Allegheny Power plant where the best ford in the Allegheny River was located.

    The west side of the Allegheny, the Springdale side, was considered Indian Territory until after the Revolutionary War, and not for settlement.