Because North Cascade peaks intercept frequent water-laden storms sweeping in from the Pacific Ocean, the range receives large amounts of rain and snow. This constant watering supports luxuriant vegetation on the west side of the range and a swarm of glaciers and snow fields on the higher peaks. From west to east the amount of precipitation changes greatly: some western valleys receive up to 160 inches of precipitation a year, whereas east of the Cascade crest, precipitation is only 10 to 20 inches.
Material in this site has been adapted from a book,
Geology of the North Cascades: A Mountain Mosaic by R. Tabor
and R. Haugerud, of the USGS, with drawings by Anne Crowder. It is published
by The Mountaineers, Seattle.