Twins Glacier in Sentinel 2 images late in the melt season in 2021, 2023, 2024 and 2025. The darker blue is bare ice and the light blue is snow cover. This illustrates the lack of significant snow covered area each of these summers.

Twins Glacier in the Wind River Range of Wyoming is nestled on the north side of a ridge extending from Winifred Peak to The Buttress, in Titcomb Basin. Titcomb Basin is high alpine basin that lacks trees and has many alpine lakes. The basin was named for brothers Charles and Harold Titcomb, who were some of the first to explore the area in 1901. The Wind River Range was inhabited by the Sheepeater Shoshone (Tukudika) tribe as far back as 2000 BC. This tribe relied on bighorn sheep as a key staple and did not utilize horses, both adaptations useful for alpine terrain. Fur trappers were active in the region going back to the 1830s including Charles Fremont for which Fremont Peak on the east side of the basin is named. Titcomb Basin remains popular with climbers today.  

Devisser and Fountain (2015) identified Wind River Range glaciers lost 47% of their area from 1900-2006. Li et al (2025) indicate a thinning rate of 0.58 m/year on Wind River Range glaciers from 2000-2019, representing a cumulative loss of 11.6 m. The loss from 1968-2000 had been -0.08 m/year. This accelerated thinning this century has led to rapid area losses across the range. The mean June-September temperature for the Wind River (Wyoming-Division 9) rose 1.2^oC from 1900 to 2024. The mean June-September temperature exceeded 16.5^oC five times from 1900-1999 and nine times from 2000-2025. During the 1900-2024 period there is no trend in November-April total precipitation for the Wind River Division. It is the frequent warm summers that have accelerated glacier loss.

Twins Glacier in 1966 spread broadly across the mountain slope from Knapsack Col to The Buttress and had an area of 0.49 km² (GLIMS). The glacier extending close to the top of a rounded ridge does recieve wind enhanced snow deposition, but no avalanching. By 2015 the area had declined 75% to 0.13 km² and was primarily confined to an area below The Buttress (Fountain et al 2023). The 2013 image (from Bob Sihler) below illustrates a lack of snow or firn cover which indicates there is no longer a persistent accumulation zone, without which a glacier cannot survive (Pelto, 2010). From 2021-2025 each summer the glacier has lost all snow cover indicating it no longer has an accumulation zone. This has led to rapid thinning and development of a bedrock ridge that has nearly separated the glacier, note 2021 image (from Will Wickert). In 2025 the glacier lost all snowcover and was fragmenting into two sections with an area of 0.05 km² and 0.03 km² respectively. The ~50 visible annual layers indicates ice in the glacier is all from the last 75 years. The glacier is almost disappeared. The fragmentation and acceleration of area loss indicates this glacier cannot endure several more years of warm conditions that eliminates snow cover.

Twins Glacier in 2013 seen from the northeast nestled below The Buttress. The diagonal bedrock ridge that is now fragmenting the glacier is not yet evident. The lack of snow or firn cover illustrates the glacier is not retaining snow cover. This image taken by Bob Sihler.

Twins Glacier in 2021 indicating rock rib extending diagonally across the glacier. There is limited retained snow or firn cover with a month left in the melt season. There are ~50 visible annual layers. The thin nature of the glacier is also evident. This is an image taken by Will Wickert.