Grand Junction is a home rule municipality that is the seat of government and largest city of Mesa County, Colorado, United States. Grand Junction's population was 65,560 at the 2020 United States Census, making it the most populous city in western Colorado and the 17th most populous Colorado municipality overall.

As western Colorado's largest city, Grand Junction is the economic and cultural center of the Western Slope region. The city is also a transportation hub, as it is situated at the convergence of Interstate 70 and U.S. Highway 50, and is the largest city between Denver, Colorado and Salt Lake City, Utah. It is also the junction between two major branches of the Denver & Rio Grande Western Railroad. Grand Junction is also a prominent college town, home to Colorado Mesa University.

Grand Junction is the principal city of the Grand Junction metropolitan area, which had over 150,000 residents in 2020. The city is located in the heart of the Grand Valley, a large Colorado River valley stretching over 30 miles east-to-west and 5 miles north-to-south. This valley is the most densely populated area in Colorado outside of the Front Range Urban Corridor.

Grand Junction is 247 miles (398 km) west-southwest of the Colorado State Capitol in Denver. The city has a council–manager form of government. It is a major commercial and transportation hub within the large area between the Green River and the Continental Divide, and the largest city in Colorado outside of the Front Range Corridor.

The city is along the Colorado River, at its confluence with the Gunnison River, which comes in from the south. "Grand" refers to the historical Grand River, renamed the Upper Colorado River in 1921. "Junction" refers to the confluence of the Colorado and Gunnison rivers. Grand Junction has been nicknamed "River City". It is near the midpoint of a 30-mile (48 km) arcing valley, known as the Grand Valley; since the late 19th century it has been a major fruit-growing region. The valley was long occupied by the Ute people and earlier indigenous cultures. It was not settled by European-American farmers until the 1880s. Since the late 20th century, several wineries have been established in the area.

The Colorado National Monument, a unique series of canyons and mesas, overlooks the city on the west. Most of the area is surrounded by federal public lands managed by the US Bureau of Land Management. Interstate 70 connects the city eastward to Glenwood Springs and Denver and westward to Green River, Utah; Salt Lake City is reached to the west via Interstate 70 and U.S Route 6; and Las Vegas (via Interstate 70 and Interstate 15).

In September 1881, the former Ute Indian Territory was abolished and the Utes were forced into a reservation so that the U.S. government could open the area to settlers. Clinton County, Pennsylvania-born George Addison Crawford (1827–91) soon purchased a plot of land. On July 22, 1882, he incorporated the town of Grand Junction and planted Colorado's first vineyard near Palisade, Colorado, causing the area to become known as the Colorado Wine Country. Grand Junction also has a storied past with gunfighters, miners, and early settlers of the American Southwest. Prior to its incorporation as the city of Grand Junction, the community was known as Ute, and was also briefly called West Denver.

The narrow gauge Denver and Rio Grande Railroad reached Grand Junction from the southeast, from Pueblo via Gunnison in 1882, followed in 1890 by the standard gauge Rio Grande Junction Railway from the northeast, from New Castle (jointly owned by the D&RG and the Colorado Midland). These greatly contributed to the expansion and settlement of the area.

At the 2020 United States Census, the city had a total area of 25,649 acres (103.799 km2) (40.077 sq mi) including 283 acres (1.147 km2) (.443 sq mi) of water.

Grand Junction has a cold semi-arid climate (Köppen: BSk). It sits in a large area of high desert lands in Western Colorado. Winters are cold and dry, with a January mean temperature of 27.4 Â°F (−2.6 Â°C). Due to its location west of the Rockies, Grand Junction does not receive as much influence from the Chinook winds as locations in Colorado east of the Front Range, yet it does receive protection from the Arctic air masses that can settle to the east of the Rockies. This is illustrated by the fact that from December to February, highs reach 50 Â°F (10 Â°C) only 18 days. Lows drop to 0 Â°F (−17.8 Â°C) or below on 2.9 nights per year. Snowfall is low compared to much of the rest of the state, averaging 17.6 inches (45 cm) per season; only once in the entire period of record dating to 1893, has observed 10 inches (25 cm) in a calendar day, though the median is 6.3 inches (16.0 cm), and moreover, snow cover is intermittent. Snow is greatest in December and January. Spring warming is gradual but quickens when nearing June; the average last freeze date is April 25. Summer is hot and dry, with a July mean temperature of 78.2 Â°F (25.7 Â°C). Grand Junction averages 68 days a year with temperatures at 90 Â°F (32 Â°C) or above, and an average 8 days attaining 100 Â°F (38 Â°C) or more. Autumn cooling is rapid, with the average first freeze date being October 11. The area receives little precipitation year-round, averaging 9.05 inches (229.9 mm), with no real seasonal spike. Sunshine hours are abundant, even in winter, and total just over 3,200 hours per year, or 73% of the possible total.

Grand Junction is the principal city of the Grand Junction, CO Metropolitan Statistical Area.

As of the census of 2000, there were 41,986 people, 17,865 households, and 10,540 families residing in the city. The population density was 1,362.6 inhabitants per square mile (526.1/km2). There were 18,784 housing units at an average density of 609.6 per square mile (235.4/km2). The racial makeup of the city was 91.78% White, 0.60% African American, 0.94% Native American, 0.76% Asian, 0.12% Pacific Islander, 3.81% from other races, and 1.99% from two or more races. Hispanic or Latino residents of any race were 10.86% of the population.

There were 17,865 households, out of which 25.5% had children under the age of 18 living with them, 46.1% were married couples living together, 9.4% had a female householder with no husband present, and 41.0% were non-families. Of all households 33.2% were made up of individuals, and 13.8% had one living alone who was 65 years of age or older. The average household size was 2.23 and the average family size was 2.84.

In the city, 21.2% of the population was under the age of 18, 11.9% was from 18 to 24, 26.3% from 25 to 44, 22.8% from 45 to 64, and 17.9% was 65 years of age or older. The median age was 39 years. For every 100 females, there were 95.1 males. For every 100 females age 18 and over, there were 92.6 males.

The population figures are for Grand Junction only; the city abuts smaller towns and unincorporated county areas which contribute to area commerce.

The median income for a household in the city was $33,152, and the median income for a family was $43,851. Males had a median income of $31,685 versus $22,804 for females. The per capita income for the city was $19,692. About 7.5% of families and 11.9% of the population were below the poverty line, including 11.8% of those under age 18 and 9.0% of those age 65 or over.

From the time settlers arrived in the 1880s until the 1960s, three of the main economic activities in the region were farming, fruit growing, and cattle raising. Fruit orchards, particularly between Grand Junction and Palisade to the east, remain important to the region's reputation and economy to the present day. Fruits most often grown are peaches, pears, apricots, plums, cherries, and, particularly since the 1980s, grapes for wine. In this semi-arid environment, these orchards thrive from a combination of abundant sunshine and irrigation from a system of canals that divert water from the Colorado River.

Attempts were made to establish sugar beet farming and beet sugar production. The Grand Valley Sugar Company established a campaign in 1893, sending three train carloads to the Utah-Idaho Sugar Company. Several tariffs and subsidies to domestic sugar were established in the 1890s, which led to uncertainty in the market. After the 1897 Dingley Act, the company was revived in 1898 and rallied to build a sugar factory. They failed to fundraise to build the plant. At the same time, Charles N. Cox was able to organize an effort to establish a factory in 1898 as well. John F. Campion and others including James Joseph Brown, Eben Smith, Charles E. Mitchell, George Trimble, James R. McKinnie, and Charles Boettcher invested, creating the Colorado Sugar Manufacturing Company in 1899 and contracting E. H. Dyer to build a factory. The failed to succeed, so they sold the plant to local investors, who were able to make it a success. The Campion-Boettcher group then created the Great Western Sugar Company.

Retail sales have been important to the economy for decades (e.g., gasoline, and hunting- and fishing-related sales), and uranium mining-related activities have also been significant. Grand Junction was home to the Climax Uranium Mill, a now decommissioned mill that provided uranium ore to the US Atomic Energy Commission.

Education and healthcare have been important to the economy of the area, especially since the 1950s, with the rise of Colorado Mesa University and St. Mary's Hospital as leading employers in these fields.

Vast oil shale reserves were known to exist near Parachute, Colorado in the Piceance Basin. The oil embargoes of the 1970s and high gas prices resulted in major financial interest in the region. Exxon purchased rights and used Grand Junction as its seat of operations. The city and the surrounding Grand Valley became prosperous in the 1970s and early 1980s largely because of the effects of oil shale development. The United States, western Colorado in particular, has the largest-known concentration of oil shale in the world (according to the Bureau of Land Management) and holds an estimated 800 gigabarrels of recoverable oil, enough to meet U.S. demand for oil at current levels for 110 years. Known as the "Rock That Burns", the shale can be mined and processed to produce oil. In the past it was significantly more expensive than conventional oil. Sustained prices above $95 per barrel, however, may make extraction economically attractive in the coming years (see Oil shale economics). ExxonMobil pulled out of the region because of lower oil prices, which led to economic hardship in the region.

The economic bust, known as "Black Sunday" (May 2, 1982) to the locals, started with a phone call from the president of Exxon to Governor Richard Douglas Lamm, stating that Exxon would cut its losses while retaining mining rights to the (then and currently) uneconomic oil. The economic bust was felt statewide, as Exxon had invested more than US$5 billion in the state. Colorado historian Tom Noel observed, "I think that was a definite turning point, and it was a reminder that we were a boom-and-bust state ... There were parallels to the silver crash of 1893."

By 2008, the economy of Grand Junction appeared to be more diverse and stable than it had been in previous decades. Major contributors to the economy were health care, tourism, agriculture, livestock, and energy mining (gas and oil). Major energy companies had once again invested large amounts of money due to increases in oil and natural gas prices (such as in the years 2005–2008). However, a major drop (in the summer of 2008) of market natural gas prices led to reduced gas well drilling and related capital expenditures in the area, significantly slowing the Grand Junction economy in 2009. Reports given in 2009 suggested that Grand Junction had once again been hard-hit economically, with one report by April 2010 listing the area as having had the largest percentage drop in employment of any "small city" in the entire United States.

By 2008, Grand Junction was being discovered by the "nation's elite business and leisure travelers" as a destination for private jet travel, with nearby Powderhorn Resort and other ski resorts a major attraction.

According to the city's 2023 Comprehensive Annual Financial Report, Grand Junction's top employers are:

Grand Junction's Colorado National Monument was home to a stage in the Coors Classic bicycle race known as "The Tour of the Moon" due to the Monument's unique landscape.

Since 1958, the JUCO World Series has been played at Suplizio Field. The city also has a professional Minor League Baseball team, the Grand Junction Jackalopes, who play in the Pioneer Baseball League. The Jackalopes were formerly known as the Grand Junction Rockies and were a minor league affiliate of the Colorado Rockies, but became independent in 2020.

Both Suplizio Field and Stocker Stadium also host Colorado Mesa University as well as School District 51 sporting events.

The Grand Junction area has developed as a mountain biking destination, with many bikers coming from the Front Range of Colorado, the Salt Lake City area, and as far away as California to enjoy the area's abundant single-track trails. Two prominent trails are the Tabeguache and Kokopelli trails, the latter running from near Loma to Moab, Utah. Fruita, Colorado, with its 18-Road trail system, is within 10 miles of the city and has become a major mountain biking destination.

The Mesa Valley School District No. 51 provides comprehensive K–12 public education to the Grand Junction area. School District 51 operates five high schools:

In addition, the district operates numerous middle, elementary, and other types of schools, including East Middle School, Redlands Middle School, and West Middle School. District 51 partners with CMU Tech to operate a vocational school, owned and operated by Colorado Mesa University. CMU Tech was formerly named Western Colorado Community College.

Colorado Mesa University, a public university, serves as the primary provider of higher education on the Western Slope from its campus in central Grand Junction. This campus has an average enrollment of just under 10,000 students and offers a variety of degrees, including a Masters in Business Administration, Educational Leadership, and ESOL. The university also operates CMU Tech, a community college offering associates degrees and professional certificates. Also located in Grand Junction is IntelliTec College, a private for-profit technical college offering professional certificates.

The Grand Junction radio market includes all of Mesa County, Colorado. Six AM radio stations and more than 25 FM stations are licensed to broadcast from the city.

Grand Junction is serviced by one local newspaper, the Grand Junction Daily Sentinel. The Grand Junction area also receives newspaper influence from sources in the greater Denver front range area.

Grand Junction has ABC, NBC, and CBS television station affiliates under the call signs of KJCT-TV (Channel 8), KKCO-TV (Channel 11), and KREX-TV (Channel 5), respectively. Also, Grand Junction has a Fox (Channel 4) affiliate station under the call sign of KFQX that receives news from the Denver FOX affiliate, KDVR (Channel 31) at 9 pm. KLML (Channel 20) broadcasts Cozi TV programming. KRMJ (Channel 18) is the local PBS affiliate, part of the statewide Rocky Mountain PBS network.

Grand Junction Regional Airport (formerly Walker Field Airport) serves as the major airport in the area. It is the largest airport in western Colorado, and the third-largest in the state, behind Denver International Airport and the Colorado Springs Airport. As of 2024, the Grand Junction Regional Airport offers direct flights to Denver, Dallas–Fort Worth, Las Vegas, Los Angeles, Phoenix, San Francisco, and Santa Ana, as well as one-stop flights to Provo, Utah. In January 2025, the airport will begin offering one-stop flights to Hartford, Connecticut. Efforts are also underway to re-establish direct flights to Salt Lake City; these flights were originally offered until staffing shortages caused Delta Airlines to cease service to Grand Junction in 2022.

Railroad Freight service is provided by Union Pacific, with BNSF trackage rights. Amtrak, the national passenger rail system, provides service to Grand Junction Station, operating its California Zephyr daily on the UP trackage in both directions between Chicago and Emeryville, California, across the bay from San Francisco.

Bustang, Colorado's state-run bus system, provides intercity bus service to the city. There are two bus lines that include Grand Junction. The West line connects to Denver, while the Outrider line connects to Durango. Both of these have multiple stops between the final destinations, and the West line has options to transfer to alternative lines.

Grand Valley Transit (GVT) is a regional transit system serving the Grand Valley. It operates 11 bus routes in the area as well as a "dial-a-ride" service.

The city also offers a shared micromobility program that was launched in May 2023. The city has allowed the companies Bird and Lime to rent out the e-scooters via their respective mobile apps.