Unsolicited Advice for visiting the ACP

Unsolicited ACP summer visit advice

Some background on the center:


  • Aspen can get cold, even in the summer. I always pack a lightweight, compressible puffy jacket and glove liners. The latter are especially useful when biking in the mornings or evenings.
  • Because of the variable weather (both in time and altitude), consider dressing in layers. A light waterproof shell/jacket can double as a windbreaker while biking. A fleece vest is a great way to add another layer. Gloves, undershirts, etc.
  • If you are an experienced hiker/outdoorsy person with a clear idea what outdoor activities you want to pursue, then pack appropriately. Otherwise, what I suggest:
    • For most people, bring light-weight hiking shoes that you can wear all day. You may want to bring a pair of flip flops
    • If you are sure that you do not want to do even light hiking, then you can get around Aspen in sneakers.
  • Pheno workshops like to play volleyball after the ACP picnic on Tuesdays. You may want to bring clothing appropriate for this (e.g. light shorts) if you do not normally dress that way.

Useful things to bring

  • Reusable grocery bags, city market card
  • Travel-sized laundry detergent and fabric softener. (Sometimes air drying is the most effective way to dry clothes; consider bringing the types of clothes that lend themselves to air drying in a pinch.)
  • Knife sharpener, especially if you like to prepare your own food. Most of the Aspen condos are thoroughly used throughout the season and the knives can get dull.
  • Sealable tupperware or lunchbox
  • Headphones for video calls.
  • Snacks for your first day
  • A light backpack if you plan on weekend hikes
  • Plastic bags, portable tissues, small first aid kit, sun screen, bug spray, …
  • Computer stuff:
    • An extra set of chargers to leave in your ACP office


The ACP lets you borrow commuter bikes to get around town. They are very useful.

  • Bring a bike light if you think you will be biking in the evening. Aim for something easy to attach to handlebars or a helmet. The ACP is located in a neighborhood that gets very dark at night. Having a bright front light helps a lot. A rear blinker to attach to your coat or backpack is a nice bonus.
  • The ACP has bike helmets and a bike maintenance person who comes every Monday. There are plenty of bike rental places (and ebike rental places) for those who want road or mountain bikes for adventures outside the city.


Many physicists go on hikes or adventures together during the workshop. This is a great way to build lifelong mentoring/collaborative/social connections that are the lifeblood of our field.

Note that even “easy” hikes can become half-day or full day outings when accounting for travel time. Be sure to bring enough food and water.

Light adventures

  • One of the quintessential views in Aspen is the Maroon Bells over Maroon Lake. There is a free bus + paid shuttle to get there. Reserve a spot ahead of time during the busy season. You typically cannot park unless you arrive early. The shuttle brings you righ to the lake which is itself a sight. There are options for different hikes from there; the Aspen Center for Environmental Studies has a low-difficulty guided tour.
  • Aspen Saturday Farmer’s Market
  • Guided tours at the Aspen Institute (Bayer Center tour and Aspen Institute landscape tour)
  • Aspen Sun Deck at the top of Aspen Mountain, especially when there’s music going on, check the Aspen events calendar. You can pick up discount gondola tickets on your way up.

Medium Adventures

  • Ute Trail to Aspen Mountain. The view from the top of Aspen Mountain is even grander when you’ve earned it by hiking up there. You can take the gondola for free on the way back down.
  • Bike to Maroon Lake.
  • Bike to Pine Creek Cookhouse
  • Snowmass activities

Serious adventures

Some people do serious backpacking and hiking. I have nothing intelligent to offer other than an exhortation to please be safe. If you are not already an outdoorsy person or if you have never been at this altitude, you should start by assuming that there is no such thing as an ’easy’ hike.


Aspen is a great place for outdoor exercise. It was, in fact, part of Paepke’s vision for Aspen that academic pursuits would flourish in combination with a program of healthy exercise inspired by the outdoor grandeur of the place. My favorites for mornings before going to the center

  • A hike up the Ute Trail to Ute Rock.
  • A swim at the Aspen Recreation Center ($12 passes available from the ACP front desk); you can take a bus from Rubey Park to the recreation center. Towel rental is $3.
  • The Aspen Red Brick Recreation center is close to the ACP and has a bouldering wall for rock climbing enthusiasts.

Other activities

  • The Aspen Center for Environmental Studies hosts guided hikes and events. These are also great for family members.
  • Aspen Institute Tours
  • The ACP front desk has discounted tickets for Aspen Recreation Center (free bus ride)
  • Need a place to get away and do some work? The Aspen Art Museum has a nice upstairs bistro with a view of Aspen Mountain and decent Wifi. There’s also a small Starbucks near Wagner park. While the Aspen Mountain gondola is operating there is a lodge with a caffeteria, fireplace, WiFi and view of the mountains.
  • I always enjoy the curated selection of books at Explore Booksellers, Aspen’s independent bookstore.

Getting Here

The ACP provides instructions for how to reach the ACP. Lodging assignments are placed on the ACP front desk at 5pm. This is because there is a window from around noon to 5pm where the ACP accommodations are cleaned.

  • I like to arrive during the day. Your office is available by Sunday morning and one can leave their luggage there while acclimating to the altitude at the center. You can walk to town to grab a meal.
  • From the Aspen airport, there is a RFTA bus that is free to downtown. You can get off at 8th and Hallam and walk to the center, or go all the way to downtown Aspen (Rubey Park) and then pick up the bus to the Aspen Music Tent (right next to the ACP).
  • Within Aspen city you can use the Aspen Downtowner app in palce of rideshare. The Downtowner service is free (you may consider giving a small cash tip) and operates within downtown Aspen. This may be useful if you’re bringing luggage from the ACP at check in to housing on the other side of town.


I like to arrive as early as possible on the Sunday of check in. Keys to the condos are not available until 5pm to give the cleaners time in between visitors. However, the offices are free and you can leave your luggage in your office while grabbing a snack, checking your email, or otherwise acclimating to the altitude. Some things to do on the first day:

  1. Make note of the door code for the ACP (it should be in your welcome email) so you do not get locked out.
  2. Check out a bike from the unreserved bikes behind Bethe. There is a checkout form in the lobby of Smart Hall with instructions for unlocking and signing out a bike. There are helmets on the Bethe patio right outside the library. You can park your bike next to the parking lot adjacent to Smart and Stranahan Halls.
  3. Check the shelf of leftover items next to the Smart Hall front desk. (e.g. you’ll often find oats, salt, olive oil, etc.)
  4. After you have checked in and picked up instructions to your condo, bring your luggage to your new home for the next couple of weeks. If the location is nearby, you can walk. Otherwise, you can call a Downtowner ride or take the RFTA shuttle near the music tents. If you’re lucky maybe a friend with a car has shown up at check in.
  5. Once you’re settled in, do a quick inventory and head to City Market or Clark’s market to buy some food. I am usually pretty tired after bringing my luggage and prefer a quick prepared meal rather than eating out.

Daily Life

  • There are two groceries in town.
    • City Market is in central downtown and is a standard Kroger grocery. It is the more affordable of the two. It is also located next to an upscale butcher/deli and a small cafe (Jour de Fete) which makes it a great place to meet up to grab supplies and a snack before a weekend hike. City Market is a great place to get cooking staples. Be sure to pick up a free membership card to access the discount prices. Their paper bags do not have handles, so you may want to either bring or invest in reusable bags.
    • Clark’s Market is a bit further from downtown but closer to the ACP. It’s a convenient bike ride (medium length walk) from the center. It is more of a Whole Foods-style upscale grocery. While the items are consistently more expensive that City Market, you will also find lots of fresh produce and some more luxury items. The location makes it a convenient place to go if you need to pick something up for the ACP Tuesday picnic. It is near a Thai restaurant that is one of the more reasonably priced places in Aspen.
  • Affordable restaurants. Unfortunately there’s a lot of year-to-year turnover in the affordable restaurants in Aspen. Here are some staples that I have enjoyed that are still around at the time of this writing.
    • Food truck: comes to the center every weekday. The truck’s horn is the unofficial start of lunchtime. Warm food, not many vegetables. Cash only. ($)
    • Hickory House: barbecue. Not the best place for vegetarians, but close to the center and inexpensive for Aspen. . ($$)
    • Bangkok Happy Bowl Thai Bistro (also Tiki bar): located right next to Clark’s market. Solid Thai food with vegetarian options. ($$)
    • New York Pizza: located downtown. Limited seating. Good option for later in the evening when most kitchens have closed. ($)
    • Mawa’s Kitchen: located in the Aspen Business Park across the airport. The most convenient way there is to take the free RFTA bus to the airport. If I have time on my departure day, I like to check in my luggage at the airport then walk to Mawa’s for brunch. Excellent brunch (semi-upscale). ($$$)
    • Silverpeak Grill: burgers located downtown. ($$)
    • CP Burger: burgers located downtown next to the Rubey Park bus station. ($$)
    • Spring Cafe: excellent breakfast and brunch. Wifi password is posted above the cash register. ($$)

Traditions and Guidelines

  • There are a few unofficial traditional events for pheno workshops:
    • Bike rides to the Pine Creek Cookhouse
    • Volleyball after the Tuesday family barbecue. The front desk has needles for the bike pumps in case you need to pump the ball.
  • Recent traditions that we’d like to stick
    • Because of rising costs for dining and entertainment and because of the need to house some physicists in Snowmass (further from downtown Aspen), a recent 2022 pheno workshop pitched in to purchase alcohol and snacks to be consumed after business hours on the ACP patio once or twice a week.
    • When dining in groups and splitting the bill, senior participants cover a portion of the junior participants dining bills. e.g. postdocs pay up to $20 and those with permanent positions can split the remainder.
    • There’s a basketball court at the Yellow Brick Playground in the same neighborhood as the ACP. This isn’t a tradition, but I’m just putting it out there…
  • Useful guidelines
    • The center provides great spaces for interactions: your office (with the permission of your officemate), the common rooms with chalkboards, the patios, and the courtyard. You can even use the Stranahan patio and Bethe meeting room if they are not being used by another program.
    • Avoid holding discussions in spaces where you may be disrupting others, e.g. the hallways/outside someone else’s office (voices echo and the doors are not soundproof), the outdoor spaces right outside someone’s office window, near the patio during workshop talks.
    • The center is open on the weekends and is a fantastic quiet space to do work. Note that Saturday mornings can be a little noisy as the cleaning staff tidy up the buildings. Also note that the ACP staff is not in during the weekend other than to bring housing packets on Sunday at 5pm. This means that if you want coffee, you get to make the coffee. It also means that you must tidy up after yourself: empty the coffee grounds/wash the coffee pot when you’re done, turn off the lights when you leave, make sure all doors and windows are closed, etc.
    • Personally I think a a good ACP participat is present. Adventures and outdoor time is great (and even better with other physicists), but the magic of the center are the happenstance conversations that spark new ideas spontaneously around the ACP. It helps to be on site during business hours (loosely defined). Attend all of your workshop talks and the colloquia, attend talks outside your workshop, and talk to everyone. This doesn’t have to take time away from the outdoors: weekends are great times for big hikes, and I cannot count the number of times I’ve made a physics-connection with someone on the Ute trail early in the morning.
    • I suggest telling all of your collaborators that you will not be available for calls while you are at the ACP. You can make exceptions for the most urgent of items, but I suggest canceling any standing meetings and not signing up for any remote talks while you are at the center. You risk missing too much of the environment at the center, and you take away from other participants who want to be able to talk to you. Go ahead and ask some of the senior ACP members what the center was like before they had WiFi, back when you had to go the front desk to take a call. They will recall this time fondly.
    • Come prepared to give a chalkboard talk. You may or may not have the opportunity to give such a talk to your workshop, but having a topic ready to talk about will facilitate discussions.


Your ACP exit report will be read by the staff and the workshop organizers. One useful guideline for these reports is that the information will be used to summarize outcomes of each workshop and to provide support for requests for future funding.

Flip Tanedo
Flip Tanedo
Associate Professor

Flip Tanedo is a professor of particle physics who specializes in theoretical descriptions of dark matter.