According to the naturalists we hiked with in Denali, we picked the best week to visit the park. Fall has arrived at this latitude, and the tundra is turning glowing shades of yellow (willows and poplars), orange (lichens), and red (blueberries and bearberries). Two weeks ago all plants on the tundra were green, and it was difficult to distinguish one from another at any distance.

Mallory teaching us about maximum snow levels and wind direction by examining spruce trees

So what exactly is the tundra? It’s a cushy layer of moss and lichen, and a select variety of shallow-rooted plants and trees, that grow in the thin soil layer on top of permafrost, a layer of frozen soil that never thaws, even in summer. Permafrost is hard as a rock, and roots cannot penetrate it; hence, the unique collection of plants that can survive in the little bit of substrate that covers it. Rainwater cannot penetrate permafrost either. Moss on the tundra will absorb what it can, but once the moss is saturated the tundra becomes one soupy bog.

Can you guess how high the snow accumulates and from which direction the wind blows?

Hiking on the tundra is a challenge, somewhat like walking on a soft, lumpy mattress, but I was excited to try. You’re never sure just how deeply your foot will sink in to the lush bed of lichens and moss, and you could end up with a boot full of water. Hiking poles were helpful, as were gaiters and rain pants to keep our feet dry, as the going was a bit wobbly and wet. The extra effort required is tiring, but unlike hiking on hard ground, going up inclines is easier. Rather than searching for a rock, root, or indent to use as a step, you can create your own anywhere you plant your foot, essentially climbing straight up a hill. And after you’ve reached the top, you can always fall back on your mossy mattress to take a nap (referred to as “tundra napping”) and rest those weary ankles!