Fall Creek is a 34-mile (55 km) tributary of the Middle Fork Willamette River in Lane County in the U.S. state of Oregon.

Beginning in the Cascade Range, the creek flows generally west through the Willamette National Forest to enter the Middle Fork upstream of Jasper, southeast of Springfield and Eugene.

[9] Campgrounds are found at intervals along the Fall Creek National Recreation Trail and Forest Road 18.

Outgoing salmon were historically challenged by predation by piscivorous non-native fish such as largemouth bass (Micropterus salmoides) and crappie (Pomoxis spp.)

A novel study published in 2019 found that by simple, low-cost draining the reservoir to streambed for a short period each year for a number of years, salmon could more easily outmigrate and non-native warmwater fish were flushed out into coldwater, riverine conditions where they could not survive.

This strategy has resulted in improved outmigration of salmon and led to the gradual disappearance of two species of predatory invasive fish (largemouth bass and crappie) in the artificial reservoir.

The lake previously supported populations of non-native largemouth bass, crappie, bluegills, and a few trout.