Ellesmere Island is the third largest and the most northerly Arctic island. It is mainly covered by mountainous areas, which are separated by three east-west passes. Some of these mountains are covered in ice caps that spawn glaciers into the sea. The margins of the island are continuously cut with bays and fiords, but Lake Hazen is the only large water body on the island.
The Canadian Shield reaches its northernmost point at the southeastern corner of Ellesmere Island. The area is very mountainous, but covered in a huge ice cap; the shapes of buried mountains cause swellings, while taller mountain peaks crack through the ice to form nunataks up to 2200-m high. The ice cap reaches both the south and east coasts and produces many icebergs, which drift into Baffin Bay. Pim Island, just east of Fram Haven, is small, but is the largest ice-free zone in the area.
West of the Shield, along the southern border, sits a plateau that was formed in the Paleozoic. Sharp valleys cut into the plateau, one main ice cap rises out of the centre, and two smaller ice caps exist in the east and west.
The rest of the island, which is part of the Innuitian region, is formed from sedimentary rock. This highland region, with folds in the terrain that form hills towards the south, progressively get bigger and form mountains towards the north. The tallest of the Arctic peaks lies here and two ice caps reach heights of nearly 3000 m.
The coastline of Ellesmere Island is dramatic; mountains and cliffs drop as much as 2600 metres straight down to the sea. The northern end of the island fades into the Ellesmere Island Ice Shelf, a massive sheet of ice 6070-metres thick that extends 18 km off shore.