Kerr Notch - Prominent Geological Features of Crater Lake National Park
Named for Mark Brickell Kerr, a United States Geological Survey topographer, Kerr Notch's U-shaped cross-section denotes the
glacier that poured through the area and carved out Kerr Valley, where Sand Creek now flows.
This andesitic valley was beheaded with the collapse and creation of the Crater Lake Caldera during Mount Mazama's climactic eruption some 7,700 years ago
[The Geology and Petrography of Crater Lake National Park (1902) by Joseph Silas Diller and Horace Bushnell Patton]
Kerr Notch at center with Mount Scott in background, Dutton Cliff at far right and Phantom Ship at bottom center, Crater Lake National Park, photo by