The Willamette National Forest is a National Forest located in the central portion of the Cascade Range of the U.S. state of Oregon. It comprises 1,678,031 acres (6,790.75 km2). Over 380,000 acres are designated wilderness which include seven major mountain peaks. There are also several National Wild and Scenic Rivers within the forest. The forest is named for the Willamette River, which has its headwaters in the forest. The forest's headquarters are located in the city of Springfield. There are local ranger district offices in McKenzie Bridge, Detroit, Sweet Home, and Westfir.

McKenzie Bridge is an unincorporated community in Lane County, Oregon, United States, on the McKenzie River and within Willamette National Forest. It is along Oregon Route 126, about 53 miles (85 km) east of Eugene, between Rainbow and Belknap Springs. The McKenzie Bridge State Airport is about 4 miles (6.4 km) east of the community.