[7] In 2009, Bucks County workers performed an unauthorized valve repair that flushed "tens of thousands" of healthy fish[8] out of the reservoir to suffer and die on the banks downstream.

[11] Robin Run rises a short distance northwest of Lower Mountain Road in Buckingham Township, flowing southeast flowing through a small unnamed pond then through Robin Run Lake, a dammed reservoir built by Bucks County in 1971, then passing into Wrightstown Township, where it meets its confluence with Mill Creek at 1.55 river mile.

Robin Run begins in the Lockatong Formation, a sedimentary rock layer deposited in Pennsylvania, New Jersey, and New York during the Triassic Period.

[citation needed] In 2018, the United States Geological Survey was awarded a $60,000 grant to conduct a dam assessment and watershed study of Robin Run.

[12] The Lockatong is defined as a light to dark gray, greenish-gray, and black very fine grained sandstone, silty argillite, and laminated mudstone.