The Belknap Crater area near McKenzie Pass, north of the Three Sisters volcanoes in the central Oregon Cascades, was the source of one of the largest concentrations of youthful volcanism in the Cascade Range.  The basaltic to basaltic-andesite Belknap shield volcano, topped by the Belknap Crater pyroclastic cone and the Little Belknap shield volcano immediately to the east, have produced widespread late-Holocene lava flows on all sides that form an impressive panorama of youthful volcanism in the McKenzie Pass area, much of which took place between about 3000 and 1500 years ago.  Late-stage eruptions from the NE base of Belknap crater produced lava flows that traveled 15 km west into the McKenzie River valley.  The narrow McKenzie Pass highway provides seasonal access across the barren lava fields with spectacular views toward Mt. Jefferson and the Three Sisters.