Elm Creek is a major tributary of the Neosho River. It runs for over 15 miles through the heart of Allen County, and borders the Lehigh Portland Trails property on the north. The Creekside Trail follows Elm Creek for about 1.25 miles, and Cave Trail North follows Elm Creek for a shorter distance.

Major publicly-accessible points of interest along Elm Creek include the Sounthwind Rail-Trail trestle bridge, the King of Trails Bike-Ped Bridge, Elm Creek Park North and Elm Creek Park South, the Elm Creek Weir Dam, the Pump House, and the Ol’ Katy Fishing Hole. The Fon-Rie Bridge and the Hegwald Bridge span intermittent streams that flow into Elm Creek.

Fishing is permitted along the entirety of Elm Creek, on the Lehigh Portland Trails property. A Kansas State Fishing License is required. Elm Creek contains a wide variety of fish species, as well as a rich habitat for birds, crustaceans, reptiles, amphibians, and plant life.