Borden, Mackenzie King, and Brock Islands
Borden, Mackenzie King, and Brock Islands are small, have low elevations, and lie along the northwestern edge of the Arctic Archipelago. They are the most remote and inaccessible of the Arctic Islands, and were not discovered until the Canadian Arctic Expedition of 19131918.
Borden Island is dome-shaped with a maximum relief of 150 m. The northern half of the island consists of light-coloured gravel, while the south has darker terrain. The only landforms on the island are low rolling hills in the southeast. Streams run both east and west from the elevated interior to the coast, where they often intertwine to form braided river systems. Borden Island has no lakes.
Mackenzie Island lies south of Borden Island. It is covered in unconsolidated sediments and is flat in the northern and eastern sections. The Leffingwell Crags are a small group of peaks, about 24 km from the west coast, which reaches a maximum elevation of 500 m. Low north-facing escarpments line the south coast, while six rivers drain the east and braid together as they near the coastline.
Brock Island is west of Mackenzie King Island. The lowest of the three islands, Brock is nearly featureless, with only rounded hills in the southeast.