Aspen began as a silver camp. Miners came in 1879, the camp became the richest silver district in the United States in the early 1890s, and then the price of silver collapsed in 1893 and nearly everyone left. By 1930 the town had 705 people. Skiing brought it back: the Aspen Skiing Company was founded in 1946, Aspen Highlands and Buttermilk opened in 1958, Snowmass in 1967. Today the Victorian brick and the lift lines share the same few blocks.
Aspen is expensive: a 2024 survey of Presidents' Day weekend put its cheapest hotel double at 674 USD (605 EUR) a night. It is also well organized. One ticket covers four mountains with their own personalities, and free buses connect them. Five days is the right length because it is four mountains and a rest day. A big group of mixed ability will want the five days, and an expert will want more days on Highlands and Snowmass, not fewer on Buttermilk.
The plan gives each mountain a day by who it suits: Ajax on day one for intermediates and up, Snowmass on day two for everyone, Highlands on day three for experts, Buttermilk on day four for beginners and families (if anyone is learning, swap days one and four so they start on the gentle mountain), and day five off skis for the ghost town, the art museum and the silver-era hotel. Start on a Monday: lift tickets cost less on weekdays, and the Aspen Art Museum, which is closed on Mondays, is open on the Friday. If you are building a longer trip across the country, the United States page has the basics.