Holden/Marolt Mining and Ranching Museum

Aspen is a home rule municipality that is the county seat and the most populous municipality of Pitkin County, Colorado, United States. The city population was 7,004 at the 2020 United States Census. Aspen is in a remote area of the Rocky Mountains' Sawatch Range and Elk Mountains, along the Roaring Fork River at an elevation just below 8,000 feet (2,400 m) above sea level on the Western Slope, 11 miles (18 km) west of the Continental Divide. Aspen is now a part of the Glenwood Springs, CO Micropolitan Statistical Area. Founded as a mining camp during the Colorado Silver Boom and later named Aspen for the abundance of aspen trees in the area, the city boomed during the 1880s, its first decade. The boom ended when the Panic of 1893 led to a collapse of the silver market. For the next half-century, known as "the quiet years", the population steadily declined, reaching a nadir of fewer than 1000 by 1930. Aspen's fortunes recovered in the mid-20th century when neighboring Aspen Mountain was developed into a ski resort, and industrialist Walter Paepcke bought many properties in the city in the 1950s and redeveloped them. Today it is home to three institutions, two of which Paepcke helped found, that have international importance: the Aspen Music Festival and School, the Aspen Institute, and the Aspen Center for Physics.In the late 20th century, the town became a popular retreat for celebrities. Gonzo journalist Hunter S. Thompson worked out of a downtown hotel and ran unsuccessfully for county sheriff. Singer John Denver wrote two songs about Aspen after settling there. Both figures popularized Aspen among the counter-cultural youth of the 1970s as an ideal place to live, and the city continued to grow even as it gained notoriety for some of the era's hedonistic excesses (particularly its drug culture).Aspen remains popular as a year-round destination for locals, second-home buyers and tourists. Outdoor recreation in the surrounding White River National Forest serves as a summertime counterpart to the city's four ski areas. Prime residential real estate in Aspen is the most expensive of any ski resort in the world on a per-square-foot basis, according to a study of 44 global ski resorts. Aspen is the world's second-highest-rated ski resort in terms of "the quality and reliability of their conditions and their capacity to withstand climate change."

The Wheeler–Stallard House is located on West Bleeker Street in Aspen, Colorado, United States. It is an 1880s brick structure built in the Queen Anne architectural style, and renovated twice in the 20th century. In 1975 it was listed on the National Register of Historic Places. It was built by Jerome B. Wheeler, an early investor in Aspen's silver mines during its boomtown years. He and two wealthy tenants rarely spent much time in the house before the Colorado Silver Boom ended in 1893. After a decade of vacancy, it became the home of the Stallard family for much of the early 20th century, the "quiet years" when Aspen's economy was depressed and its remaining residents struggled to make a living. After World War II it was bought by Walter Paepcke, who like Wheeler came to visit Aspen and invested heavily in its development, leading to the city becoming a cultural center and upscale ski resort. He never lived there himself, and it eventually became the residence of Alvin C. Eurich during his tenure as Aspen Institute president. Since the late 1960s it has been the home of the Aspen Historical Society, which operates it partially as a historic house museum.

The Aspen Center for Physics (ACP) is a non-profit institution for physics research located in Aspen, Colorado, in the Rocky Mountains region of the United States. Since its foundation in 1962, it has hosted distinguished physicists for short-term visits during seasonal winter and summer programs, to promote collaborative research in fields including astrophysics, cosmology, condensed matter physics, string theory, quantum physics, biophysics, and more.To date, sixty-six of the center’s affiliates have won Nobel Prizes in Physics and three have won Fields Medals in mathematics. Its affiliates have garnered a wide array of other national and international distinctions, among them the Abel Prize, the Dirac Medal, the Guggenheim Fellowship, the MacArthur Prize, and the Breakthrough Prize. Its visitors have included figures such as the cosmologist and gravitational theorist Stephen Hawking, the particle physicist Murray Gell-Mann, the condensed matter theorist Philip W. Anderson, and the former Prime Minister of the United Kingdom, Margaret Thatcher.In addition to serving as a locus for physics research, the ACP’s mission has entailed public outreach: offering programs to educate the general public about physics and to stimulate interest in the subject among youth.

Pioneer Park, also known as the Henry Webber House or the Webber–Paepcke House, is located on West Bleeker Street in Aspen, Colorado, United States. It is a brick structure erected in the 1880s, one of the few such homes in the city. In 1987 it was listed on the National Register of Historic Places. Henry Webber, its builder, was a shoe merchant who grew wealthy from his mining investments during Aspen's original growth during the Colorado Silver Boom. The house is said to be haunted by the ghost of his wife Harriet, who died under controversial circumstances. It is the only intact house in the Second Empire architectural style in the city, particularly on the interior. At one time it was owned by Walter Paepcke, the Chicago businessman who led Aspen's mid-20th-century renaissance as a ski resort town.While Paepcke owned the house, he invited Albert Schweitzer to Aspen to give the keynote speech at a festival he organized to commemorate Johann Wolfgang von Goethe's bicentennial. It was Schweitzer's only visit to the U.S., and he stayed in the carriage house at the rear of the property. Today that building, a contributing resource to the Register listing, is known as Schweitzer Cottage. The house remains a private residence.

The Matthew Callahan Log Cabin is located on South Third Street in Aspen, Colorado, United States. It was built in the early 1880s. In 1987 it was listed on the National Register of Historic Places along with a group of other historic properties in the city. It was one of many log cabins built during Aspen's earliest years of settlement. Today it is one of the few buildings left in the city from that era, and the only one from prior to 1885 with hand-hewn logs. It has been expanded, but the original structure remains intact.

The Samuel I. Hallett House is located on West Francis Avenue in Aspen, Colorado, United States. It is a timber frame structure built in the late 19th century. In 1987 it was listed on the National Register of Historic Places. It was originally a log cabin built by one of the miners who came to Aspen in its earliest years of settlement, during the Colorado Silver Boom. Samuel I. Hallett, who later expanded it, was an officer of the Smuggler Mine, one of Aspen's largest and most lucrative. When its owners renovated it in the mid-20th century, they discovered the remnants of the original log cabin. Since then it has been through multiple owners, and remains a private residence.

The D. E. Frantz House is located on West Bleeker Street in Aspen, Colorado, United States. It is a wooden frame house constructed for a local lumber magnate during the 1880s in the Queen Anne architectural style. It has remained a private residence ever since and is largely intact. In 1987 it was listed on the National Register of Historic Places along with other historic properties in the city. Included in the listing is a small barn in the back, although the date of its construction is not known.It is the only Victorian house in Aspen that retains its oriel window. The extension of the gabled roof on one side to shelter the porch is also a unique feature within the city. At the time it was listed it was owned by a longtime community leader.

Aspen Meadows is a 40-acre conference center and resort located amongst the Rocky Mountains in Aspen, Colorado. It is owned by the Aspen Institute, and is the venue for some of the institute's events, such as the annual Aspen Ideas Festival and Socrates Program seminars. It was designed by Herbert Bayer in the Bauhaus style.

The Smith–Elisha House, sometimes known just as the Elisha House or the Christmas Tree House, is located on West Main Street (State Highway 82) in Aspen, Colorado, United States. It is a wood frame structure in the Queen Anne style built in the late 19th century. In 1989 it was listed on the National Register of Historic Places. It is considered one of the best Queen Anne houses in the city. Eben Smith, its original owner, was a mine owner during Aspen's boomtown years who worked to improve mine safety. Mansor Elisha, its other titular owner, was an accidental owner of the Hotel Jerome who later became mayor. Since those times it has remained intact.

The Davis Waite House is located on West Francis Street in Aspen, Colorado, United States. It is a wooden structure in Victorian architectural styles built during the 1880s. In 1987 it was listed on the National Register of Historic Places along with several other historic properties in the city. Davis H. Waite, an early owner, was one of the founding publishers of The Aspen Daily Times. He was later elected governor of Colorado. After a single term he returned to Aspen. Later owners included Herbert Bayer, an Austrian architect extensively involved in the mid-20th-century renovation of Aspen, and Robert Orville Anderson, an oil executive who was chairman of the Aspen Institute board.The property includes two small outbuildings, one of which is a more modern one that has been connected to the main house since its construction. The unconnected one is believed to be one of Aspen's few remaining original log cabins, now covered in clapboard, and is thus considered a contributing resource to the National Register listing. All buildings have remained largely intact.

The Shilling–Lamb House, also sometimes referred to as Victoria House, is located on North Second Street in Aspen, Colorado, United States. It is a wood frame structure in the Queen Anne architectural style built around 1890. In 1987 it was listed on the National Register of Historic Places. It is unique among Aspen's Queen Anne houses both for its minimal decoration and its corner tower. The name comes from its first two occupants. In the later 20th century it was the home of Edgar Stanton, a cofounder of the Aspen Music Festival and School who established its training program for recording engineers. It has remained a private residence, largely intact from the time of its construction.

The Bowles–Cooley House is located at the corner of West Francis and North First streets in Aspen, Colorado, United States. It is a brick structure in the Queen Anne architectural style built during the 1880s. In 1987 it was listed on the National Register of Historic Places along with many other historic properties in the city. It is one of the few large brick houses built in Aspen during its early boomtown era, and one of the largest houses built in the city's West End. The name comes from its first two residents, a local lumber merchant who built it and a mining lawyer. Many years later it would be the home of Red Rowland, vice president of the Aspen Skiing Company and manager of the Aspen Mountain ski area. It is considered an excellent local example of the Queen Anne style, and has been preserved relatively intact. It continues to be a private residence.