Perhaps Sam Johnson's greatest legacy was preserving the headwaters of the Metolius River, also known as Metolius Springs. The headwaters are just north of Black Butte, and are unusual because the Metolius River emerges from an underground volcanic lava tubes as a full flowing river. For many years, the Johnsons allowed public access to the scenic headwaters viewing area. The Johnsons gave the Metolius Springs viewing site to the United States Forest Service in 1965. Today, the area is managed as a Forest Service park.