For most of the summer, only the first 15 miles (to Savage River) of the Park Road are open to private vehicles. This portion is paved and makes for an excellent day trip. From early May, when the road is plowed, to late May, when the shuttle buses start running, it is possible to drive as far as the Teklanika River rest area at Mile 30. The road beyond this doesn’t open until late May, so early arrivals to Denali National Park [1] will not be able to see many of the sights for which it is famous.
At the end of summer, the Park Road is opened to auto traffic for four days in mid-September. Only 400 vehicles are allowed per day, and passes are selected by a lottery. In a typical year, you may be competing with 10,000 other entries for these passes! You’ll need to apply during July, but contact the Park Service (907/683-2294, www.nps.gov/dena [2]) for details.
A handful of professional photographers are allowed vehicular access to the park during the summer, but these slots are highly sought after, and may involve giving up your first-born child and opening your home as a lodging place for all Park Service employees who might be passing through.
Links:
[1] http://www.moon.com/destinations/alaska/the-interior/denali-national-park
[2] http://www.nps.gov/dena