[3] Fourmile Creek starts in Greene Township, immediately north of Pennsylvania Route 8.

[6] In a list of 22 tributaries of Lake Erie compiled in a Strategic Action Plan, Fourmile Creek was ranked as the fourth-lowest in water quality.

[2] A stream in the watershed of Fourmile Creek received sewage discharges for at least 20 years in the 1900s.

[2] Fourmile Creek has eroded through glacial and lake sediments and into the underlying bedrock, which consists mainly of shale from the Devonian period interbedded with sandstone and siltstone.

[3][8] In its upper reaches, Fourmile Creek flows through a relatively narrow valley that is 30 feet (9.1 m) deep.

[10] As of 2011, two aluminum fishways have been added to allow steelhead trout to bypass river obstacles and improve access to their spawning grounds.

In 2012, a golf course adjacent to these improvements finalized legal easements granting public access to the fishways via their private property.

[12] Pine trees grow densely in the valley in the upper reaches of Fourmile Creek.