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.

Aspen Center for Physics has limited resources to assist prospective participants who may encounter issues entering the United States. ACP can send prospective participants an official letter of acceptance that may facilitate the process. For assistance please email acp@aspenphys.org. Be sure to allow enough time for the visa process.

To get here, you may drive, fly, or take a shared shuttle van. Due to the excellent, free bus system, the Center’s bike fleet, and the town’s walkability, generally you do not need a car during your stay.

If you are flying, please make reservations far in advance since flights to Aspen often sell out. Please note that some flight options are seasonal.

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).

Aspen Airport will be closed May 5 –  June 1, 2025. Please see other airport options below. 

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

Eagle County Airport

There are also direct flights to Eagle County Airport (about 1.5 hours or less by car from Aspen) from many major cities. You can take buses from the Eagle Airport to the Aspen Center for Physics, instructions here. You can also take the Roaring Fork Express (advance reservations required.)

Grand Junction Airport

Flying to Grand Junction Regional Airport (about 2 – 2.5 hours by car from Aspen) is an option. It may make sense to fly to Grand Junction and drive, as the drive is flatter and shorter than the drive from Denver.

Denver Airport

Many participants choose to fly to Denver and take ground transportation to Aspen (a 4+ hour drive.) See options for Ground Transportation from Denver to Aspen below.

By Shared Shuttle Van or Bus or Train

• Shuttle service via Roaring Fork Express (5 hours, advance reservations required, by phone (970) 486-3002). (From Denver Airport to Aspen and Eagle Airport to Aspen).
• The Bustang runs from downtown Denver (Union Station) to Glenwood Springs.
  • Take the RTD A-line train from the Denver Airport to Union Station. $10 for one-way ticket.
  • Catch the Bustang from Union Station to Glenwood Springs. It’s the “West Line.” Check the schedule in advance. It’s approx. $28.
  • Then you can take the RFTA bus the rest of the way to Aspen. Approx $5-10.
  • This is the most economical but also the timing can be tricky. The final Bustang leaves Denver (Union Station downtown) at 5:15pm.
• The Amtrak California Zephyr train runs from Denver to Glenwood Springs where you can transfer to a local RFTA bus to Aspen. 

By Car / Rental Cars

Rental cars are typically available at all of the airports listed; however you may want to make reservations in advance for the best rates.

If you are driving from Denver, note that there are two route options:

• Easiest: Interstate 70 West to Glenwood Springs and then Highway 82 southeast to Aspen – This route is a little longer in distance but avoids the two-lane road through the mountains over Independence Pass.
• More Difficult: Interstate 70 west to Copper Mountain, Highway 91 south/southwest through Leadville to Highway 82 at Twin Lakes, and then west/northwest to Aspen. The last 40 miles of this drive takes you on a two-lane, paved mountain road over scenic Independence Pass. There are narrow sections. Note: Highway 82 over Independence Pass is tentatively scheduled to open for 2025 at the end of May (exact date TBD). Please check COtrip to ensure the road is open before deciding to take this route.

Carpool / Ride Share

If you are interested in sharing a car ride to Aspen, please check the new ACP Carpool List to share your rental car or request a ride with another physicist. ACP staff does not monitor this list, but we’ve provided it as a tool to help physicists coordinate rides with each other.

• If you know you are renting a car, and willing to share, click the blue “Add” to put in your details.
• If you are trying to find a car to join and none exist yet, click the yellow “+Join Waitlist” on the side (or bottom if on mobile) and you can add your details. Another physicist may reach out, but we suggest checking back to see if anyone has added their rental car in the main section that you can join.

Please see our page about Local Transportation here.

Please see our guide to Transportation with Children here.