Geological Survey Professional Paper 705—A Inventory of Glaciers in the North Cascades, Washington

The first census of glaciers in this country described glaciers on the higher volcanic peaks of the Cascade Range (Russell, 1885). Russell (1897) later recognized that there also were glaciers in the non-volcanic mountains of the North (or Northern) Cascade Range, known popularly as the North Cascades. Because of the remoteness and inaccessibility of the interior of this mountainous area, the extent of the glacier cover was not recognized for many decades. Recent attempts at a glacier census were more complete owing to aerial photographs and better maps. An inventory taken by Meier (1961) included 519 glaciers in the North Cascades, covering a total area of 252 km² (square kilometers).

A comprehensive inventory is now appropriate as part of a program of the International Hydrological Decade (1965-74).¹ Objectives of the IHD, outlined at the first meeting of its Coordinating Council in 1965, include a "world inventory of perennial ice and snow masses" (Resolution I—12). The world inventory is being taken under the technical direction of a working group of the International Commission of Snow and Ice of the International Association of Scientific Hydrology (IASH). This program provides a synoptic look at an estimated 80 percent (the frozen part) of the world's fresh water resources. It also provides important background data for the Permanent Service on the Fluctuations of Glaciers, recently established at Zurich, Switzerland.

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¹The International Hydrological Decade (IHD) is a cooperative program of many countries working individually and collectively to advance the knowledge of water and hydrological processes. UNESCO is a coordinating agency for the IHD.

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This census of glaciers in the North Cascades is the first American contribution to the "world inventory of perennial ice and snow masses." It has been estimated (Meier, 1961) that 77 percent of the glacier area in the United States south of Alaska occurs in the State of Washington and that 63 percent of that glacier area is in the North Cascades. Thus, the present inventory covers about half of the glacier area in the United States south of Alaska. Later inventories will cover other glacierized areas of the country.