Crary Mountains () are a group of ice-covered volcanoes in Marie Byrd Land, Antarctica. They consist of two or three shield volcanoes, named Mount Rees, Mount Steere and Mount Frakes, which developed during the course of the Miocene and Pliocene and last erupted about 30,000-40,000 years ago. The first two volcanoes are both heavily incised by cirques, while Mount Frakes is better preserved and has a wide caldera at its summit. Boyd Ridge is another part of the mountain range and lies southeast of Mount Frakes; it might be the emergent part of a platform that underlies the mountain range. The volcanoes consist mainly of basalt, trachyte and phonolite in the form of lava flows, scoria and hydrovolcanic formations. Volcanic activity here is linked to the West Antarctic Rift system, which is responsible for the formation of a number of volcanoes in the region. During their existence, the range was affected by glaciation and glacial-volcanic interactions. Geography and geomorphology The mountain range lies in eastern Marie Byrd Land, Antarctica, about from the Bakutis Coast. It was first visited in 1959–1960, and several accessible outcrops were sampled. The name refers to Albert P. Crary, who was then Deputy Chief Scientist for the US-IGY Antarctic Program. The Crary Mountains are a chain of three shield volcanoes long which extends in northwest-southeast direction. The volume of the volcanoes exceeds and the edifices consist of lavas, hydrovolcanic deposits such as hyaloclastite, fragments of pillow lavas and tuffs, and scoria. Unlike many other mountains in Marie Byrd Land, which owing to a lack of erosion display only their highest and youngest parts, in the Crary Mountains the internal structure of the volcanoes are well exposed due to glacial erosion. The Crary Mountains form a drainage divide for the West Antarctic Ice Sheet; they dam it, which is thus higher on the southwestern side of the range. Debris stripes have been observed on the ice near the foot of the mountains. The northeasternmost volcano is Mount Rees, which reaches a summit height of at Tasch Peak. Volcanic rocks crop out at Trabucco Cliff on its northeastern flank. There is no caldera. Glacial erosion has cut deep cirques into the eastern flank of Mount Rees, and volcanic outcrops indicate that volcanic rocks alternate between subglacial formations and subaerial formations. Outcrops consist of breccia and lavas, which in one case are intruded by a dike. In the middle