Numerous moraines front the Coe Glacier on the north side of Mount Hood, Oregon. These moraines were identified and dated using a multiple methodology approach in order to establish a chronology for the advances and stillstands of the Cae Glacier. This chronology was compared to chronologies established for other glaciers on Mount Hood, North Sister, Mount Rainier and Mount Baker as well as glaciers in Scandinavia. The chronology was also compared to a long term temperature record from Longmire, Washington. The maximum identified extent of the pre-Little Ice Age Coe Glacier was indicated by moraines located at an elevation of about 1530 m and about 2 km downvalley of the present terminus. A general period of shrinkage of the pre-Little Ice Age Coe Glacier followed resulting in the deposition of moraines upvalley of the older pre-Little Ice Age moraines. The Little Ice Age Coe Glacier reached its maximum downvalley extent of about 1650 m elevation prior to 1731 AD. An earlier advance (1607 AD) was more extensive laterally than the 1731 AD advance. The Coe Glacier has been in a general state of recession since the mid to late 1700's. The prominent lateral moraines formed prior to 1882 AD. Four low moraines located within the Coe Glacier trough formed before 1901. Historical records indicate that the Coe Glacier has generally continued to recede since then. A comparison of the moraine ages and the historical activity of the Coe Glacier to other glaciers on Mount Hood as well as others in the Pacific Northwest and Scandinavia reveals that fluctuations of the glacier termini are generally synchronous. This similarity, combined with the similarity of the ages of Coe Glacier moraines to cool periods in a long term temperature record, indicates that hemispheric climatic patterns have played a major role in the past fluctuations of the Coe Glacier.

This research documents the Holocene glacial history of Mount Hood, Cascade Mountains, Oregon by analyzing a set of three lateral moraines abutting Eliot Glacier, the largest glacier on the mountain. This study seeks to: 1) establish the relative ages of these lateral moraines and 2) determine if these features represent distinct glacial advances. The hypothesis is that the lateral moraines for Eliot Glacier represent three distinct periods of glacial advance based on their position relative to the current glacier and other diagnostic indicators. Soil profiles of three positions (shoulder, backslope, and footslope) on the distal side of each lateral moraine were described in the field and samples were taken from each horizon for laboratory analyses of pH and particle size. The results of the soil analysis show that the soils developing on the moraine closest to the current glacier are poorly developed and significantly younger than the other two features. The closest moraine likely dates to the Little Ice Age (600-150 YBP) and has soils with an A/C profile and a classification of Andic Cryopsamment. The soils on the middle and furthest moraines from the glacier are similar in the profile sequence (Andic Haplocryepts). Silt bulges were noted in the mid-slope pits. The furthest moraine has deeper horizons and more color development than the middle moraine. Ash layers were found in the backslope soil profile (36-51cm deep) on the middle moraine. Additional lab testing confirms the ash layers originated from Mount Hood, but no date can be assigned. The eruptive history of Mount Hood points to the Timberline eruptive period (1,500 YBP) as a likely candidate for one of the ash deposits. This evidence suggests the middle moraine was actively forming during this period and is intermediate in age between the furthest moraine and the Little Ice Age Moraine; hence, this sequence of moraines indicates three distinct periods of glacial advance in the Neoglacial.