The most convenient place for visitors to rent a car is at Denver International Airport. Most major agencies have offices in Eagle County Airport as well.
Although it is often severely overcrowded, I–70 is still the quickest and most direct route from Denver to Vail. For the first 45 minutes it climbs gradually through the dry Front Range mountains before ducking into the Eisenhower Tunnel. The last 45 minutes are through the high Summit County Basin and up and over the mellow grade of Vail Pass.