Editing North Cascades National Park (section)

=== Glaciers ===
[[File:Eldorado Peak view east.jpeg|thumb|View of three glaciers from Eldorado Peak: Inspiration, Forbidden, and Quien Sabe|alt=A view looking down on a range of dark mountains. The valley to the left contains a light-colored glacier. There is a small lake at the bottom of the picture.]]
With approximately 312 glaciers, North Cascades National Park has the most glaciers of any US park outside Alaska, and a third of all the glaciers in the lower 48 states.<ref name=riedel1>{{cite web|last=Riedel|first=Jon|author2=Mike Larrabee|author3=Sharon Brady|author4=Niki Bowerman|author5=Rob Burrows |author6=Steve Dorsch|author7=Joanie Lawrence|author8=Jeannie Wenger|title=Glacier Monitoring Program|publisher=National Park Service|url=http://www.nps.gov/noca/naturescience/glacial-mass-balance1.htm|access-date=March 29, 2018}}</ref> Counting a few glaciers in the adjoining National Recreation Areas, the North Cascades National Park Complex glaciers covered an expanse totaling {{convert|27000|acre|sqkm}} as of 2009.<ref name=riedel2>{{cite web|last=Riedel|first=Jon|author2=Michael Larrabee|title=North Cascades National Park Complex Glacier Mass Balance Monitoring Annual Report, Water Year 2009|work=Natural Resource Technical Report NPS/NCCN/NRTR&ndash;2011/483|publisher=National Park Service|url=http://www.nps.gov/noca/naturescience/upload/134_NCCN_NOCA_GlacierAnnualReport2009_20110825.pdf|date=August 2011|access-date=March 30, 2018}}</ref> [[Boston Glacier]], on the north slope of Boston Peak, is the largest glacier in the park, measured in 1971 to have an area of {{convert|1730|acre|sqkm}}.<ref name=student/> Other glaciers that were measured in 1971 to be larger than {{Convert|2|km2}} include [[East Nooksack Glacier|East Nooksack]] and [[Sulphide Glacier]]s on [[Mount Shuksan]], [[McAllister Glacier|McAllister]] and [[Inspiration Glacier]]s on Eldorado Peak, [[Redoubt Glacier]] on [[Mount Redoubt (Washington)|Mount Redoubt]], [[Neve Glacier]] on [[Snowfield Peak]], and [[Challenger Glacier (Washington)|Challenger Glacier]] on Mount Challenger.<ref name=post>{{cite web|last=Post|first=Austin|author2=Don Richardson|author3=Wendell V. Tangborn|author4=F. L. Rosselot|title=Inventory of Glaciers in the North Cascades, Washington|publisher=U.S. Geological Survey|url=https://pubs.usgs.gov/pp/0705a/report.pdf|access-date=June 22, 2018}}</ref>

[[File:Lowercurtis.jpg|thumb|left|Lower Curtis Glacier in 2003 compared to 1985 extent demarcated by red line demonstrates the retreat of this glacier.|alt=A dark mountain range showing the end of a glacier. There is a timestamp in orange: "08.07.2003". A red line well below the end of the glacier is marked "1985".]]
The dense concentration and relative ease of access to the North Cascade glaciers brought about some of the earliest series of scientific studies regarding glaciology in the United States. Beginning in 1955, the [[University of Washington]] sponsored [[Richard C. Hubley]] to undertake annual aerial photography expeditions designed to capture images of the glaciers and to show any alterations that might be occurring.<ref name=post2>{{cite book|last1=Post|first1=Austin|author2=Edward R. LaChapelle|title=Glacier Ice|date=March 1, 2000|publisher=University of Washington Press|isbn=978-0802083753|url=https://books.google.com/books?id=BofiWpPh328C&q=Richard+C.+Hubley&pg=PR12|access-date=March 30, 2018}}</ref> In 1960, [[Austin Post (photographer)|Austin Post]] expanded the aerial coverage to include other regions and he also used ground-based imagery to augment the research. In 1971, based on the photographs and other data collected since 1955, Post and others wrote a report that documented the number and scale of glaciers in the North Cascades.<ref name=post/> At the time of Austin Post's inventory, their study concluded that some North Cascades glaciers had experienced a period of minor growth or equilibrium in the mid-20th century, after undergoing decades of retreat. The study concluded that annual glacial melt due to seasonal variations has a significant influence on river levels, accounting for about 30&nbsp;percent of the late summer water flow, which directly impacted the supported ecosystems such as salmon fisheries.<ref name=post/>

The National Park Service, United States Geological Survey (USGS) and [[glaciologist]]s such as [[Mauri S. Pelto]], who has led the North Cascades Glacier Climate Project since 1984, have continued research on North Cascade glaciers.<ref>{{cite journal|last=Pelto|first=Mauri|title=Vanishing Glaciers|journal=Washington Trails|pages=1–4|date=September 2007|url=http://www.wta.org/magazine/1240.pdf|access-date=March 30, 2018}}</ref> Since 1993, the National Park Service has conducted rigorous studies on four park glaciers: [[Noisy Creek Glacier|Noisy Creek]], [[Silver Glacier|Silver]], [[North Klawatti Glacier|North Klawatti]] and [[Sandalee Glacier]]s.<ref>{{cite web|title=Glaciers Selected for Monitoring|publisher=National Park Service|url=http://www.nps.gov/noca/naturescience/glacial-mass-balance2.htm|access-date=March 30, 2018}}</ref> The National Park Service research indicated that these four glaciers experienced rapid decrease in volumes between 1993 and 2011.<ref>{{cite web|title=Recent Trends in Glacial Volume|publisher=National Park Service|url=http://www.nps.gov/noca/naturescience/glacial-mass-balance6.htm|access-date=March 28, 2018}}</ref> In 1998, a National Park Service and [[Portland State University]] aerial photographic inventory showed a 13&nbsp;percent loss in park-wide glacial volume since Austin Post's inventory in 1971.<ref name=trends>{{cite web|title=Long Term Trends|publisher=National Park Service|url=http://www.nps.gov/noca/naturescience/glacial-mass-balance7.htm|access-date=March 30, 2018}}</ref> The NPS stated that in the last 150&nbsp;years since the end of the [[Little Ice Age]], a period of several centuries in which the earth experienced a cooling phase, glacial ice volumes in the North Cascades have been reduced by 40&nbsp;percent.<ref name=trends/> This loss of glacial ice has contributed to decreased melt in the summer. In a paper published in 2016, it was reported that since 1959 the Skagit River watershed has seen a 25&nbsp;percent reduction in the summertime streamflow.<ref>{{cite web|title=Glacier Monitoring Program|url=https://www.nps.gov/noca/learn/nature/glacial-mass-balance1.htm|publisher=National Park Service|access-date=June 27, 2018|date=January 19, 2018}}</ref>