Columbine, Colorado

The Columbine High School massacre, commonly referred to as Columbine, was a school shooting and attempted bombing that occurred on April 20, 1999, at Columbine High School in Columbine, Colorado, United States. The perpetrators, twelfth-grade students Eric Harris and Dylan Klebold, murdered twelve students and one teacher. Ten of the twelve students killed were in the school library, where Harris and Klebold subsequently committed suicide. Twenty-one additional people were injured by gunshots, and gunfire was also exchanged with the police. Another three people were injured trying to escape. The Columbine massacre was the deadliest mass shooting at a K-12 school in U.S. history, until it was surpassed by the Sandy Hook Elementary School shooting in December 2012, and later the Robb Elementary School shooting in May 2022, and the deadliest mass shooting at a high school in U.S. history until the Parkland high school shooting in February 2018. Columbine still remains both the deadliest mass shooting and the deadliest school shooting to occur in the U.S. state of Colorado. Harris and Klebold, who planned for at least a year and hoped to have a large number of victims, intended for the attack to primarily be a bombing and only secondarily a shooting. But when several homemade bombs they planted in the school failed to detonate, the pair launched a shooting attack. Their motive remains inconclusive. The police were slow to enter the school and were heavily criticized for not intervening during the shooting. The incident resulted in the introduction of the immediate action rapid deployment (IARD) tactic, which is used in active-shooter situations, and an increased emphasis on school security with zero-tolerance policies. Debates and moral panic were sparked over American gun culture and gun control laws, high school cliques, subcultures (e.g. goths), outcasts, and school bullying, as well as teenage use of pharmaceutical antidepressants, the Internet, and violence in video games and movies. Many makeshift memorials were created after the massacre, including ones employing victims Rachel Scott's car and John Tomlin's truck. Fifteen crosses for the victims and the shooters were erected on top of a hill in Clement Park. The crosses for Harris and Klebold were later removed following controversy. Planning for a permanent memorial began in June 1999, and the resulting Columbine Memorial opened to the public in September 2007. The shooting has inspired dozens of copycat killings, dubbed the Columbine effect, including many deadlier shootings across the world. The word "Columbine" has become a byword for school shootings.

Columbine High School (CHS) is a public high school in Columbine, Colorado, United States, in the Denver metropolitan area. It is part of the Jefferson County Public Schools district.In 1999, it became the scene of an infamous mass shooting, where 12 students and one teacher were murdered by senior students Eric Harris and Dylan Klebold before the pair committed suicide.

Plum Creek is a stream in Douglas County, Colorado, United States. It is formed by the confluence of West Plum Creek and East Plum Creek near the intersection of North Perry Park Road and Manhart Avenue in Sedalia. Prior to the construction of Chatfield Reservoir in the 1960s and 1970s, Plum Creek merged with the South Platte River in far northern Douglas County. Now, however, it empties into the southern side of the reservoir itself, just west of Santa Fe Drive and within the boundaries of Chatfield State Park. The Chatfield Storage Reallocation Project, scheduled to start in fall, 2017, will add capacity to Chatfield Reservoir and raise its level about 12 feet. This higher reservoir level will cause the mouth of the creek to move about 7,000 feet further upstream. As part of the expansion project, a mitigation project will also be undertaken to deal with increased sediment deposition and channel erosion along Plum Creek caused by increased urban runoff.

The 1967 PGA Championship was the 49th PGA Championship, played July 20–24 at Columbine Country Club in Columbine Valley, Colorado, a suburb south of Denver. Don January won his only major title in an 18-hole playoff over Don Massengale (69-71). Both had overtaken the leaders with low scores in the fourth round on Sunday. Columbine was scheduled to host the championship in 1966, but flooding of the course by the South Platte River caused a postponement of a year. Firestone Country Club in Ohio, scheduled to host in 1967, swapped years with Columbine and was the site of the tournament in 1966.There was a possibility of a boycott of the championship by the top tournament players, due to grievances with the PGA of America. An understanding was achieved several weeks before and the top players entered.At the time, Columbine was the longest course in major championship history at 7,436 yards (6,799 m). The elevation of the course is over 5,300 feet (1,620 m) above sea level, additionally dry and fast conditions shortened its effective length. Tommy Aaron carded a course record 65 in the second round to take a four-stroke lead, but a 76 on Saturday dropped him two back and he fell out of contention on Sunday with a 78. The 54-hole leader was Dan Sikes, the chairman of the tournament players committee, who shot a final round 73 and finished a stroke out of the playoff, in a tie for third with Jack Nicklaus.This was the second and final 18-hole Monday playoff at the PGA Championship, formerly a match play event through 1957. The next playoff was ten years later in 1977 and the format was changed to sudden-death, immediately following the fourth round. It was later changed to a three-hole aggregate format, first used in 2000. The Open Championship was played the previous week near Liverpool, England, one of five times in the 1960s that these two majors were played in consecutive weeks in July. The PGA Championship moved permanently to August in 1969, where it remained through 2018 (except 1971, when it was played in late February). In 2019, the tournament moved to the weekend before Memorial Day.

Southwest Plaza is an enclosed shopping mall in unincorporated Jefferson County, Colorado, immediately south of Denver. Littleton, Colorado is commonly indicated in the mall's postal address because its ZIP code is primarily associated with that city, which lies some two miles east. The mall has two levels with over 150 stores and a food court. The anchor stores are Dillard's, Dick's Sporting Goods, Round 1 Entertainment, and JCPenney. There are 2 additional anchor spaces, with one serving as a Macy's fulfillment center and a vacant anchor spot last occupied by Sears.

The Town of Columbine Valley is a Statutory Town located in western Arapahoe County, Colorado, United States. The town population was 1,502 at the 2020 United States Census, a +19.59% increase since the 2010 United States Census. Columbine Valley is a part of the Denver-Aurora-Lakewood, CO Metropolitan Statistical Area and the Front Range Urban Corridor.

Chatfield Dam and Reservoir is a dam and artificial lake located on the South Platte River, south of Littleton, Colorado. The dam and reservoir were built by the United States Army Corps of Engineers as a response to the disastrous flood of 1965. In addition to its primary purpose of flood control, it serves as one of many water supply reservoirs for the city of Denver, Colorado. In 1966, the U.S. Atomic Energy Commission projected a total federal cost of $74 million. Construction of the project was begun in 1967 and the dam was completed in 1975. The massive breastworks of the dam measure approximately 13,136 feet (4,004 m) in length with a maximum height of the dam of 135 feet (41 m) above the streambed. The normal depth of the lake is 59 feet (18 m) at its deepest point. This means the dam towers 88 feet (27 m) above the mean surface of the reservoir. The lake drains an area of more than 3,000 square miles (8,000 km2). The 1,500 acre (6 km2) lake has a conservation storage capacity of 27,000 acre⋅ft (0.033 km3) with a flood-control pool of over 350,000 acre⋅ft (0.43 km3)

Marston Lake is a reservoir in Denver, Colorado. It is owned by Denver Water and was completed in 1902. The reservoir sends water to the Marston treatment plant, and from there the water is distributed to Denver residents. The reservoir receives water from the South Platte River. The river receives water from the Colorado Western Slope through a transmountain diversion via the Roberts Tunnel.

Bow Mar is a Statutory Town located in Arapahoe and Jefferson counties, Colorado, United States. The town population was 853 at the 2020 United States Census with 587 residing in Arapahoe County and 266 residing in Jefferson County. Bow Mar is part of the Front Range Urban Corridor. The current mayor of Bow Mar is Bryan Sperry.

Littleton–Mineral station (sometimes styled as Littleton•Mineral) is a RTD light rail station in Littleton, Colorado, United States. Operating as part of the D Line, the station was opened on July 14, 2000, and is operated by the Regional Transportation District. Presently this serves as the southern terminus for the D Line; however, RTD plans to extend this line south to Highlands Ranch.

Ken Caryl, commonly known as Ken Caryl Ranch, is an unincorporated community and a census-designated place (CDP) located in and governed by Jefferson County, Colorado, United States. The CDP is a part of the Denver–Aurora–Lakewood, CO Metropolitan Statistical Area. The population of the Ken Caryl CDP was 33,811 at the United States Census 2020. The Ken Caryl Ranch Metropolitan District and the Ken Caryl Ranch Water District provide services. The Littleton post office (Zip code 80127) serves the area.

Hildebrand Ranch is located near Littleton, Colorado. In 1866 Frank and Elizabeth Hildebrand settled in Deer Creek and homesteaded on 160 acres. In the 1950s there was a plan that was authorized to control flooding in Denver but the funds never came. In 1971 the Army condemned 333.73 acres of the ranch and created Chatfield Reservoir. In March 1973 Denver leased 750 acres from Chatfield and 67 for the Denver Botanic Gardens which included the ranch's original buildings. In February 2001 Jefferson County Open Space purchased 1,450 acres of Hildebrand Ranch