It takes about two hours to fly to Denver from Los Angeles or Dallas, and 2½ hours from Chicago. From New York and Boston the flight is about 4½ hours. If you'll be checking skis, arrive even earlier.
The major air gateway to the Colorado Rockies is Denver International Airport (DEN), usually referred to by its nickname, DIA. It's about 25 miles northeast of downtown Denver and 45 miles from Boulder. Flights to smaller, resort-town airports generally connect through it. Inclement weather, fairly common in winter, occasionally delays or cancels flights. In recent years, the airport has expanded its restaurant offerings to include higher-end spots like Elway’s steak house and the Denver Chophouse, but also includes more casual fare. Currently, all airport hotels are located 7 miles west toward Denver, but an airport expansion slated to open in late-2015 will include a 14-story luxury hotel next to the airport's terminal.
Colorado Springs Airport (COS) has direct flights from many major cities and is slightly less subject to bad winter storms than Denver. The airport is sometimes still open when bad weather closes other airports (especially those in the ski towns). Some of the major airlines and their subsidiaries serve communities around the state: Grand Junction (GJT), Durango (DRO), Steamboat Springs (HDN), Gunnison–Crested Butte (GUC), Montrose (MTJ), Telluride (TEX), Aspen (ASE), and Vail (EGE). Some major airlines have scheduled service from points within the United States to Colorado Springs Airport (COS); the relatively mild weather in Colorado Springs means that its airport is sometimes still functional when bad weather farther north and west affects the state's other airports. Many ski towns increase their seasonal service, adding direct flights.
Colorado Springs Airport (COS). Colorado Springs, Colorado. 719/550–1900; flycos.coloradosprings.gov.
Denver International Airport (DEN). Denver, Colorado. 800/247–2336; www.flydenver.com.
If you are driving, the best route from Denver International Airport to Denver, the ski resorts, or the mountains is to drive west on I–70. You can bypass some traffic by using the E–470 tollway, which you can access west of the airport. It connects to I–25 both south and north of Denver. When flying into Colorado Springs, take I–25 north and south. Vail, Aspen, Telluride, and the surrounding towns are accessible on Highway 24 without going through Denver.
RTD, the city's public transit, has frequent bus service to Denver and Boulder; visit their booth in the main terminal for destinations, times, and tickets. There are taxis and various private airport shuttles to cities along the Front Range from the airport, and some offer door-to-door service. Many hotels and ski resorts have their own buses; check with your lodging or ski resort to see if they offer service. The Ground Transportation Information Center is on the fifth level of the main terminal, and can direct travelers to companies' service counters.
If you’re transferring between Denver International and Colorado Springs airports, this is easily done with your originating airline if you are flying Allegiant Airlines, American, Continental, Delta, Frontier, Northwest Airlines, United, or US Airways. If you choose, bus and shuttle services are available through Ramblin Express or Supershuttle.
Denver International Airport (DEN) has direct flights from most major U.S. cities, as well as quite a few smaller ones, especially in the West. A few international carriers serve Denver with nonstop flights from London, England; Frankfurt, Germany; Tokyo, Japan; Reykjavik, Iceland; as well as Canadian cities like Vancouver, Toronto, and Montréal. United Airlines, Southwest Airlines, and Frontier Airlines (based in Colorado) are Denver's largest carriers, with the most flights and the longest list of destinations. Colorado Springs is served by Allegiant Airlines as well as by most major domestic airlines. United Express and Great Lakes Airlines connect Denver with smaller cities and ski resorts within Colorado.
Aero Mexico. 800/237–6639; www.aeromexico.com.
Air Canada. 888/247–2262; www.aircanada.com.
Alaska Airlines. 800/252–7522; www.alaskaair.com.
Allegiant Airlines. 702/505–8888; www.allegiantair.com.
American Airlines. 800/433–7300; www.aa.com.
British Airways. 800/247–9297; www.britishairways.com.
Delta Airlines. 800/221–1212; www.delta.com.
Frontier. 800/432–1359; www.frontierairlines.com.
Great Lakes. 800/554–5111; www.flygreatlakes.com.
JetBlue. 800/538–2583; www.jetblue.com.
Lufthansa. 800/645–3880; www.lufthansa.com.
Southwest Airlines. 800/435–9792; www.southwest.com.
United Airlines. 800/864–8331; www.united.com.
US Airways. 800/428–4322; www.usairways.com.