Lower Curtis Glacier is located in North Cascades National Park

North Cascades National Park

North Cascades National Park is a U.S. National Park located in the state of Washington. The park is the largest of the three National Park Service units that comprise the North Cascades National Park Service Complex. Several national wilderness areas and British Columbia parkland adjoin the...

, in the U.S. state

U.S. state

A U.S. state is any one of the 50 federated states of the United States of America that share sovereignty with the federal government. Because of this shared sovereignty, an American is a citizen both of the federal entity and of his or her state of domicile. Four states use the official title of...

 of Washington. Named for photographer Asahel Curtis

Asahel Curtis

Asahel Curtis was a Pacific Northwest photographer.-Birth:Asahel Curtis was born in 1874 in Minnesota to Johnson Asahel Curtis , a reverend; and Ellen Sheriff .-Parents and siblings:...

, the glacier is in a cirque

Cirque

Cirque may refer to:* Cirque, a geological formation* Makhtesh, an erosional landform found in the Negev desert of Israel and Sinai of Egypt*Cirque , an album by Biosphere* Cirque Corporation, a company that makes touchpads...

 on the western slopes of Mount Shuksan

Mount Shuksan

Mount Shuksan is a glaciated massif in the North Cascades National Park. Shuksan rises in Whatcom County, Washington immediately to the east of Mount Baker, and south of the Canadian border. The mountain's name Shuksan is derived from the Lummi word [šéqsən], said to mean "high peak". The highest...

. Lower Curtis Glacier is rapidly retreating and has a negative mass balance

Glacier mass balance

Crucial to the survival of a glacier is its mass balance, the difference between accumulation and ablation . Climate change may cause variations in both temperature and snowfall, causing changes in mass balance. Changes in mass balance control a glacier's long term behavior and is the most...

, meaning that the rate of snow and ice that is falling in the accumulation zone

Accumulation zone

On a glacier, the accumulation zone is the area above the firn line, where snowfall accumulates and exceeds the losses from ablation, . The annual Glacier equilibrium line separates the accumulation and ablation zone annually...

 is less than that which is lost each year in the ablation zone

Ablation zone

Ablation zone refers to the low altitude area of a glacier or ice sheet where there is a net loss in ice mass due to melting, sublimation, evaporation, or calving. The ablation zone is delineated by the equilibrium line altitude , or snow line, which separates the ablation zone and the high...

. Between 1908 and 1984, the glacier experienced a loss of thickness by 45 meters (147 ft). Between 1984 and 2002, the glacier lost another 6 meters (19 ft) in thickness. Lower Curtis Glacier also lost 28% of its surface area between the end of the little ice age

Little Ice Age

The Little Ice Age was a period of cooling that occurred after the Medieval Warm Period . While not a true ice age, the term was introduced into the scientific literature by François E. Matthes in 1939...

(around 1850) and 1950. Between the years 1951 and 1979, the glacier actually lengthened by 245 meters (800 ft) but has retreated 184 m (600 ft) since 1985, partly due to the tongue of the glacier being on a steep precipice which may have increased the loss of ice at the termini.