The Ogilvie, Wernecke and
Selwyn Mountains form a broad mountainous band across the north
central Yukon. Bedrock and colluvium characterize steep, rugged
slopes at higher elevations.
Rounded valleys and scattered cirques throughout most of these
highlands show that these mountains were glaciated. The northeast
slopes of the highest peaks in the Selwyn Mountains, such as Keele
Peak and the Itsi Range, are still glaciated. In contrast, the
'castellations', castle-like rock outcrops along ridge summits,
and long scree slopes characterize the unglaciated Northern Ogilvies.
Permafrost is common and near surface permafrost occurs in fine
textured sediments on lower slopes.
The Ogilvie-Wernecke-Selwyn mountains are a major barrier to the prevalent winds resulting in increased cold and precipitation on their southeast slopes. Due to winter inversions, temperatures at higher elevations are relatively moderate with the most severe winter temperatures encountered in the valley bottoms.
Alpine tundra dominates higher elevations. Open black spruce forests and woodlands are common on moist permafrost slopes and drier uplands. White spruce forests are usually limited to river valleys at lower elevations.
Numerous Yukon rivers have their headwaters in this area. The Ogilvie, Blackstone, Hart, Wind, Bonnet Plume and Snake rivers all flow north to the Peel River. The North Ogilvies drain north into the Porcupine River. The Klondike, Stewart, Hess, Ross and Macmillan flow west to the Pelly and Yukon rivers. In the southeast, the Hyland and Coal rivers are south-flowing tributaries of the Liard.