Traveling and Visa Information

The Aspen Center for Physics is located in the town of Aspen, Colorado, in the Rocky Mountains West of Denver, well-known as a ski resort in winter and for hiking and other outdoor activities in summer.

Traveling to Aspen

Aspen has its own airport (ASE), about 10 minutes out of town. It is served by United Airlines, American Airlines, and Delta Airlines with nonstop flights from Atlanta, Denver, Chicago, Dallas/Fort Worth, Houston, Los Angeles, Minneapolis, Phoenix, Salt Lake City, and San Francisco (this list is subject to change).

There is a free bus from the Aspen airport to the Aspen Center for Physics. Plan your route with the Transit app here, or use the RFTA trip planner here. Typically, a bus comes every 15-20 minutes, depending on the season. You can get on the “BRT”, “L”, or “SM” at the airport, and get off at the “Hallam Street + 8th” stop to walk a few blocks to the Center.

Some participants choose to fly to Denver and take ground transportation to Aspen, about a 4-hour drive (over many scenic mountain passes).
Ground transportation options from Denver airport include:

  • Shuttle service via Roaring Fork Express (5 hours, reservations required in advance. Make a reservation online here or by phone: (970) 486-3002).
  • The Bustang, whish runs from Denver, CO to Glenwood Springs, CO where you can transfer to a local RFTA bus to Aspen.
  • Rental car (one way rentals are available).
  • Shared ride found through the Center’s Ride Board.

Another alternative is to fly to Eagle/Vail and take ground transportation (1.5 hours via Roaring Fork Express, see information above).

If you choose to drive your own car to Aspen, you will be able to park for free at the Center and at your housing. Please make sure to get a parking pass from the front desk. If you will have multiple cars with you (if you are bringing family), please let us know in advance, as some of our housing units only come with one spot. 

Visa Information

If you need a letter of invitation to process your visa, contact the Center at Be sure to allow enough time for the visa process as it has been taking longer than in years’ past.

“It turned out that I got the crucial idea for the solution for one of the two problems I solved during my stay during a hike, and not while sitting in the office. This might indicate that an exceptional environment is a ‘promoter’ for scientific work.”

— Michael Ratz