Boulder, Colorado

**Boulder** is a city in the state of Colorado, in the United States. It is the county seat of Boulder County. Boulder is in the foothills of the Rocky Mountains. The city's height is . It is  northwest of Denver. In 2020, there were 108,250 people living the City of Boulder. The Boulder Metropolitan Statistical Area has 330,758 people living in it.

Boulder is famous for its history and its Western . In the late 1960s, lots of hippies moved to Boulder. The main campus of the University of Colorado, the University of Colorado at Boulder, is also here. CU Boulder is the biggest university in Colorado.

## History
On November 7, 1861, the government decided to build a university in Boulder. The legislature decided that the university would be run by the state. The first building was built in 1875. The cornerstone for the Old Main Building was laid on September 20, 1875. The university was officially opened on September 5, 1877.

In 1907, the city of Boulder passed an anti-saloon ordinance. This law said that saloons and bars could not do business in the city, and that people could not drink alcohol. In 1916, the entire state of Colorado started prohibition. In US History, the "Prohibition Era" was a time when all alcohol was illegal. People could not make, drink, buy, sell, or serve alcohol. Prohibition ended in 1933, when the Twenty-first Amendment to the United States Constitution was passed by Congress.

## Demographics
The 2020 United States Census said there are 108,250 people living in the City of Boulder. These people make up 43,565 households. The population density was 4,111.7 people per square mile (1,587.5 people/km²). According to the census, the people living in Boulder are 78.8% White, 1.3% black or African-American, 0.6% Native American, 6.4% Asian, 0.1% Pacific Islander, 4.7% of another race, and 8.1% of two or more races. 10.6% of the population are Hispanic or Latino of any race. The city gets its water from Arapahoe Glacier and Boulder Creek.

### Climate
Boulder has a dry climate. It has many sunny or mostly sunny days every year. According to the Köppen climate classification, the city's climate is "semi-arid" (Köppen *BSk*). Winters are cool, but sometimes can get very cold. During the winter, the high temperature is usually in the mid- to upper- 40s°F (7–9 °C). The low temperature in winter can be below −10 °F (−23 °C) on a few nights. Usually it does not stay below 0 °F (−18 °C) for many days at a time. 

Even though it is cold in the winter, Boulder does not get as much snow as the mountains. This is because of something called orographic lift. This means that the mountains in the west dry out the air as it passes over the Front Range. By the time the air gets to Boulder, most of the water and snow has been removed. Sometimes there are heavy snow storms, but not too often. The average amount of snow in Boulder is  per season, total. Usually only a few inches fall at a time. Because Boulder is so high up, the sun is very strong and hot, so the snow melts quickly. Sometimes Chinook Winds will make the temperature go up quickly and have the snow melt even faster.

Summer in Boulder is hot and dry. Usually there are 27 days during the summer that reach  or above. It is much cooler at night because of how high up the city is. The hottest temperature ever was on June 23, 1954 and July 11, 1954. On those days it was . The coldest temperature was in February 1989 and December 1990, when it was .

## Politics and government
Boulder is a Home Rule Municipality. In Colorado, this means that Boulder's government was formed according to three different legal documents. These documents are: Article XX of the Constitution of the State of Colorado; Title 31, Article 1, Section 202 of the Colorado Revised Statutes; and Boulder's own Home Rule Charter. 

Boulder is very liberal and very Democratic. , registered voters in Boulder County were 41% Democrat, 20% Republican, 1% other parties, and 38% unaffiliated (not any specific party.) Boulder County includes the conservative suburbs of Boulder.

Boulder was the first city in Colorado to pass a law that made it illegal to discriminate against people because of their sexual orientation. This law was passed by the Boulder City Council in 1974. The law was repealed (cancelled) by the voters that same year. In 1975, Boulder became the second city to ever grant a same-sex marriage license. The license was given by Boulder County Clerk Clela Rorex. Soon after a law was passed that said that marriage licenses could not be given to people of the same gender. In 1987, the people of Boulder voted again to make it illegal to discriminate against people because of their sexual orientation. This was passed by popular vote. Boulder became the first city in the United States that had this kind of a law that was passed by a direct vote of the people.

## Sister cities
Boulder has seven official sister cities:
*  Dushanbe, Tajikistan (May 8, 1987)
*  Jalapa, Nueva Segovia Department, Nicaragua (1983)
*  Kathmandu, Nepal (2018)
*  Kisumu, Kenya (2008)
*  Lhasa, Tibet, China (1986)
*  Ciudad Mante, Mexico (2000)
*  Nablus, West Bank, Palestine (2016)
*  Ramat HaNegev, Southern District, Israel (2018)
*  Yamagata, Japan (1994)
*  Yateras, Guantánamo Province, Cuba (2002)

There are several  in Boulder in honor of the sister cities. The Sister City Plaza was dedicated in May 17, 2007. It is on the east lawn of Boulder's Municipal Building. The plaza was built in honor of Boulder's relationships with its sister cities.

## Sources