Sun Valley's history began in 1935, when Averell Harriman, chairman of the board of Union-Pacific Railroad, sought to establish North America's first destination ski resort. After searching the West, he chose Ketchum, Idaho—a mining town surrounded by mountains. 

The resort's construction began in May 1936 on the 3,200-acre former Brass Ranch. Sun Valley Lodge opened in December 1936, followed by the Swiss-style Sun Valley Inn in 1937 and The Ram restaurant in 1938—a long-time celebrity favorite and Sun Valley's oldest restaurant. 

By 1937, Sun Valley had become a year-round destination. The golf course, designed by William Bell, opened in summer 1938, along with the Sun Valley Opera House. Trail Creek Cabin, built in 1937, opened to the public in the 1940s.

With Sun Valley Resort’s location set, Union Pacific engineer Jim Curran revolutionized skiing by using his experience engineering banana conveyor systems that loaded fruit onto ships to design a way to safely transport skiers uphill.

Construction began on Dollar Mountain and Proctor Mountain in summer 1936, making Sun Valley the birthplace of the modern chairlift. The ski runs were designed by Charles Proctor, one of America's foremost ski pioneers, and Proctor Mountain was named in his honor. Remnants of the world's first chairlift terminal are still visible on Proctor Mountain today. 

Bald Mountain—"Baldy"—opened for alpine skiing in December 1939, offering a 9,150-foot summit and 3,400-foot vertical drop.

Averell Harriman enlisted New York publicity agent Steve Hannagan to introduce Sun Valley Resort to the world. Hannagan coined the resort's name and first tagline—"Winter sports under a summer sun"—while orchestrating the celebrity visits that put Sun Valley on the map.  

Ernest Hemingway became the resort's most famous resident, spending twenty years living on and off in Sun Valley until his death. He first visited in 1939 and finished his novel For Whom the Bell Tolls in Room 206 of the Sun Valley Lodge. Hemingway is buried in the Ketchum Cemetery, forever linking his legacy to the resort. 

The iconic Roundhouse Restaurant opened in January 1940 at 7,700 feet of elevation on Bald Mountain, its octagonal design and 46 windows offering panoramic views. The Sun Valley Lodge Bowling Alley—one of the Northwest's oldest—was installed in the basement that summer.  

Hollywood's love affair with Sun Valley continued as Sun Valley Serenade (1941) starring Sonja Henie was filmed on location. The resort temporarily closed in 1942 during World War II, was converted to a U.S. Navy convalescent hospital, and reopened in December 1945.

Ski filmmaker Warren Miller got his start here in the late 1940s, living in a teardrop camper in the resort parking lot while creating his first film, which premiered at the Sun Valley Opera House. 

In 1964, regular passenger rail service to Ketchum ended, and Sun Valley was sold to Janss Investment Company, led by Olympic skier Bill Janss, the founder of Snowmass. Under Janss, Bald Mountain underwent major expansion in Warm Springs and Seattle Ridge terrain. 

Baldy grew from 33 to 62 trails with seven new chairlifts added. In 1965, the first double chairlifts opened on Warm Springs, including Limelight lift with its 2,200-foot vertical rise—America's greatest at the time. 

The late '60s saw Sun Valley become the birthplace of freestyle skiing through locals Bobbie Burns and Jim Stelling, who pioneered "hot dogging" techniques on Baldy's Exhibition, Limelight and Lower Holiday runs. 

In 1972, brothers Jake and Dave Moe launched Powder Magazine in Ketchum to showcase freestyle skiing. Sun Valley legitimized the sport in 1973 by hosting the first U.S. Freestyle Championships. 

Lookout Lodge opened on Bald Mountain's summit in 1973. Snowmaking was introduced on Warm Springs in 1975, covering 100 acres up to 8,200 feet—the highest elevation anywhere at that time.  

The Seattle Ridge double chairlift opened in December 1977, christened by ski racing legend Gretchen Fraser. In 1977, Janss sold Sun Valley to Utah businessman Earl Holding, ushering in the third era of ownership with the Holding family. 

Clint Eastwood brought his Western, Pale Rider, to Sun Valley in 1985, showcasing Sun Valley's rugged terrain beyond the ski slopes. 

Bald Mountain access improved dramatically with four new high-speed quad chairlifts installed. The on-mountain dining experience evolved as well—Warm Springs Lodge replaced the old North Face Hut in 1992, followed by Seattle Ridge Lodge opening in 1993. 

Carol's Dollar Mountain Lodge opened in 2004, enhancing the family-friendly skiing experience on Dollar Mountain.

The Sun Valley Pavilion opened in August 2008, built with marble from the same Roman quarry that supplied stone for the Colosseum and St. Peter's Basilica.

That same year, the golf experience expanded with the 9-hole White Clouds course and the Sun Valley Club, a full-service clubhouse designed to match the resort's mountain day lodges.

In 2009, the Roundhouse Express Gondola opened, whisking guests from River Run base to the mid-mountain Roundhouse restaurant. 

The Roundhouse underwent a complete remodel in 2010 to welcome guests year-round, expanding beyond its traditional ski season operations.

The Sun Valley Lodge received its most recent interior renovation in 2016 to provide more space for guests while ensuring the historic property maintained its timeless elegance.  

The resort's wellness offerings reached new heights in 2015 with the opening of the 20,000-square-foot state-of-the-art Spa at the Sun Valley Lodge. 

Sunrise Expansion & New Broadway Lift (2020):  
In summer 2020, the resort’s then oldest chairlift, Cold Springs #4, was replaced with a high-speed detachable quad lift. The Sunrise Expansion added 388 acres of new skiable terrain for the Winter 2020-21 season. 

Warm Springs Enhancement Project (2023):  
Guests were introduced to a new Warm Springs experience in Winter 2023-24, with two new high-speed lifts, a trail extension, and additional gladed skiing. The old Challenger and Greyhawk lifts were replaced by a Doppelmayr 6-pack covering 3,138 vertical feet in 8 minutes. The new Flying Squirrel 4-pack carries skiers from the base to mid-mountain, while the extended Lower Flying Squirrel trail provides easier access to Warm Springs terrain.

Seattle Ridge Enhancement Project (2024):  
The new Seattle Ridge chairlift, a detachable six-person Doppelmayr lift, opened in December 2024, improving skier circulation on Bald Mountain's Seattle Ridge side. 

World Cup Course Construction on Warm Springs (2024-25): 
To host the 2025 Audi FIS Ski World Cup Finals, Sun Valley underwent a major transformation. A-net safety structures expanded from 9 to 72 towers across the mountain. Snowmaking was enhanced with 34 new guns and 10,000 yards of pipe. The mountain received a complete digital upgrade for timing and broadcast equipment. Course construction included reshaping the finishing area and doubling the width of Baldy's International run, creating the newest Downhill addition.

From the resort's earliest days, Sun Valley has attracted top-level ski racers with technical and challenging terrain, setting the standard for high-level competition from the very beginning. 

Key Racing Dates: 
1937 | First Harriman Cup 
1948 | Gretchen Fraser Wins Gold in St. Moritz 
1974 | World Pro Skiing Lange Cup on Dollar Mountain 
1975 & 1977 | World Cup Races: World Cup racing came to Greyhawk in the late ‘70s, where longtime Sun Valley Ski Education Foundation (SVSEF) coach Abi Fisher was a top competitor

1980 | World Pro Skiing Volvo Cup 
1984 | Christin Cooper Wins Silver in Saravejo 
1998 | Picabo Street Wins Gold in Nagano 
1998 | Muffy Davis Wins Bronze in Nagano 
2016 & 2018 | Sun Valley Hosts U.S. Alpine National Championships 
2023 & 2024 | Sun Valley Hosts U.S. Alpine National Championships 
2025 | Sun Valley Hosts Audi FIS Ski World Cup Finals