Tips and Special Features
This unit follows the historic trail used by the pioneer climbers of Denali, including the first expeditions to reach both the North and South Summits. The end of the "trail" is McGonagall Pass with great views of Denali, the Muldrow Glacier and the Alaska Range. The best time to cross the McKinley River is very early or late in the summer season so it can be difficult to get a permit for this area during those times. If Unit 20 is full, similar terrain can be found in Units 19 and 21 and you are unlikely to run into any other parties or signs of people. Another option, if you have the proper equipment and training, is to float over the McKinley River during the summer using pack rafts.
Access
There is no road access to this unit. The most common access starts by leaving the Park Road about 0.25 miles east of the Wonder Lake Campground and hiking down the McKinley Bar Trail to the McKinley River (Unit 14). There is no established route or bridge to the south side of the McKinley River where Unit 20 starts. The river changes course each year and you must plan on finding your own way across it. In a typical year, a good crossing strategy is to hike up stream for about half a mile and then begin to angle your way across toward the western end of the spruce patch on the south bank.
Common Routes and Hiking Corridors
The main route to McGonagall Pass along the informal climbers' trail is the most commonly used part of the unit. Plan on spending at least four nights in this area if you want to reach McGonagall Pass, and plan to hike strenuously for most of those days. A more pleasant trip is to plan on 5 to 7 nights to enjoy the scenery and wait out foul weather.
Crossing the McKinley River should only be attempted by backpackers with previous major river crossing experience. This is a large, glacier-fed river and it is extremely difficult to cross for most of the summer, even in sections where it is heavily braided. It is best to cross the river early in the morning, meaning it is ideal to spend your first night in Unit 14 or 15 and crossing the next day.
The unmaintained 'climber's trail' is very difficult to find on the north side of the McKinley River Bar and is not maintained. Hikers should travel from Wonder Lake Campground via the established McKinley Bar Trail. The start of the unmaintained 'climber's trail' is across the river and about 1 mile upstream (i.e., east) from where the McKinley Bar Trail meets the McKinley River. Many hikers find it easier to find from Turtle Hill; so if you have trouble finding it along the river, head for the summit of that small hill.
After Turtle Hill, the informal 'trail' is fairly obvious, but a map and good cross-country travel skills are still required to avoid becoming confused by the many animal trails and stream crossings. The 'trail' is muddy and brushy in many areas until you reach upper Cache Creek and its open tundra fields. The last two miles to McGonagall Pass are a cross-country route through the talus and boulder fields.