Colorado has 20 zip codes with a median listing price over $1 million.

Pitkin County has long had a reputation as the most expensive real estate market in the state, but the number of zip codes in Colorado where the median list price is above the $1 million mark is now soaring to 20, according to a study by the real estate portal RealtyHop.

Aspen’s 81611 remains the most exclusive real estate market in the state, with a median list price this year of $3.67 million. That’s where Colorado joined the elite club of $100 million-plus home sales with the purchase of 419 Willoughby Way for a state record $108 million in April.

Not far behind is 81654 in Snowmass, where the median list price is $3.49 million, and third place is 81435 in Telluride, where the median list price is $3.39 million.

RealtyHop looked at real estate listings in each state through October of this year to determine which zip codes had the highest median list price in each state. The median is the midpoint, where half of the listings are priced higher and half are priced lower. List prices are not the same as the final sale price, although the two tend to follow each other.

Among Colorado’s 642 ZIP codes, ski resorts dominate the price list for the most expensive homes, with Vail’s 81657 having a median list price of $1.97 million, while Aspen’s neighbor Snowmass Village , 81615, has a median list price of $1.93 million. Just north of the Aspen and Snowmass area is 81623, which has a median list price of $1.89 million. It once again includes affordable towns like Marble, Redstone, and Carbondale.

Aspen’s wealth effect also carried over to 81621, which includes Basalt and El Jebel, where the median list price is $1.83 million. Likewise, 81632 ZIP, which includes Avon, Wolcott and Edwards west of Vail, is in the top 20 with a median list price of $1.82 million.

Other ski resort communities in the top 20 are Summit County’s 80424, home to Blue River, Breckenridge, Frisco and Keystone for $1.72 million; 80487 in Steamboat Springs at $1.69 million and 81224 in Crested Butte at $1.35 million.

Three Boulder County ZIPs made the list, led by Boulder’s 80304 at $1.42 million, mountain towns west of Boulder in 80302 at $1.34 million and south Boulder’s 80305 at 1 .15 million dollars.

Two other Front Range ZIPs were on the list. They include 80116 in Castle Rock, Franktown and The Pinery in Elbert and Douglas counties, where the median list price was $1.31 million, and 80135 ZIP in Sedalia and surrounding areas with a median list price of $1.19 million.

If access to mountains and ski resorts has helped define Colorado’s most expensive real estate markets, beachfront properties near major cities have defined the most expensive real estate markets in the country.

The most expensive ZIP code in the country, for the fifth year in a row, is 94027, in Atherton, California, where the median list price is $7.75 million, according to RealtyHop. The Silicon Valley enclave in San Mateo County allows only one house per acre and has a population of about 7,000.

Next is 33109, home to Fisher Island in Miami-Dade County, Florida. The median list price is $6.1 million in the exclusive southern enclave of South Beach, on a coral reef island.

The third most expensive ZIP, according to RealtyHop, is 11962 in Suffolk County, New York. Sagaponack is part of the East Hamptons and represents old money with a median list price of $5.99 million.