At 7,000–8,000 feet, the ponderosa forests of the Transition zone yield to thickets of Gambel oak near the rims. On the North Rim, lupine and butterweed make purple and yellow carpets below the ponderosas during the summer. Above 8,000 feet, the North Rim Canadian zone is home to white fir, while the moister and cooler Hudsonian zone is typified by spruce-fir forests.

These two zones do not have distinct boundaries, but interweave with each other according to topography, so they are often referred to in combination as the Boreal life zone. The Boreal life zone receives 25–30 inches of precipitation annually, supporting forests of spruce and fir, with open meadows edged by aspen, shimmering yellow and gold in fall. The first major snowfall often arrives in November.

Temperatures sometimes plummet below zero, and snows can last into May or even June. High-meadow lakes form from snowmelt in the spring, attracting coyotes, wild turkeys, deer, elk, and other wildlife.