Once you cross the East Fork River at Mile 44 (there is great hiking out onto the flats from here), you begin your ascent of Polychrome Pass, one of the most spectacular and sphincter-clamping sections of the road. If you’re scared of heights or become frightened at the 1,000-foot drop-offs, just do what the driver does—close your eyes.
These rocks have a high iron content; the rate of oxidation and the combination of the iron with other minerals determine the different shades of rust, orange, red, and purple. Look and listen for hoary marmots in the nearby rocks, and from here almost the rest of the way to Eielson Visitors Center [1], watch for caribou and wolves; these are the Murie flats, where wildlife biologist Adolph Murie studied the lifestyle of Canis lupus.
Descend to the Toklat River at Mile 53, the last and largest you cross before Eielson. This is the terminus of the wildlife tour, but the shuttle buses continue on to Eielson and Wonder Lake. The Toklat’s source is the Sunrise Glacier, just around the bend upriver (left). You can see from the size of the river how big the glacier was 20,000 years ago. There is great hiking up into the Alaska Range from here.
Next you climb up Stony Hill and, if the weather is cooperating, when you crest the ridge you’re in for the thrill of a lifetime: Denali, The Great One, in all its immense majestic glory. It’s hard to believe that the mountain is still 40 miles away! But wait, you get another five miles closer, crossing Thorofare Pass, the highest elevation (3,950 feet) on the road, at Mile 62.
Links:
[1] http://www.moon.com/destinations/alaska/the-interior/denali-national-park/heading-out-the-park-road/eielson-visitors-center