English: Cloud-free view of the archipelago. Although Parry Channel appears partially ice free, especially in the east, sea ice spans most of McClure Strait, blocking the northern, or preferred, route through the Northwest Passage. The southern route, however, which Roald Amundsen followed from 1903 to 1906, appears open. Snow-free land surfaces allow a view of the islands’ topography. While the western end of Baffin Island appears flat and almost featureless, dramatic stripes cross Bathurst Island in the north-west. These approximately east-west stripes result from layers of exposed bedrock, likely tilted by a mountain-building event in the mid-Mesozoic Era. Snow-free landmasses vary in colour from beige to brown. Cold temperatures, persistent snow cover, and short growing seasons limit tree growth so far north, leaving the islands coated with tundra.