According to the United States Census Bureau, the city has a total area of 8.9 square miles (23.1 km²), of which, 8.9 square miles (22.9 km²) of it is land and 0.1 square miles (0.2 km²) of it (0.67%) is water.
Lafayette quickly became a part of the coal mining boom that all of eastern Boulder and southwestern Weld counties were experiencing, with the Cannon and Simpson mines being the largest and most productive. By 1914 Lafayette was a booming town with two banks, four hotels and a brickworks. Lafayette was also the location of a power station that served Louisville, Boulder, Longmont and Fort Collins.
Mary Miller continued to be a leader in the community, especially in January 1900 when the town burned. She founded the Miller Bank in 1892, which became the Lafayette Bank in 1902. She was elected President of the bank and at that time was the only woman bank president in the world. The bank closed in 1914 because of roughly $90,000 in bad loans to the United Mine Workers. She remained devoted to the temperance movement and eventually ran for State Treasurer on the Prohibition ticket. Miller died in 1921 at her daughter-in-law's home at 501 E Cleveland St.
Lafayette continued to thrive as a coal mining town. Many miners struck in the aforementioned strike in the 1910s, which was nationally recognized as a great Wobbly (Industrial Workers of the World; a radical labor group) strike; noted for the Ludlow Massacre of miner's families by the national guard in the Southern Coal Field near Trinidad.
In 1927, Lafayette's coal miners struck again. This time, the mining massacre was closer to home, resulting in the deaths of 5 Lafayette resident miners just northeast of town at the Columbine Mine Massacre on November 27, 1927, in what is now the ghost town of Serene near Erie.
Strangely, it was another female financier who came to the miners' aid again - Ms. Josephine Roche, the daughter of the anti-labor deceased owner of the Rocky Mountain Fuel Company that owned many of the mines in the Lafayette area, used some shares of the company she had inherited from her father and bought a controlling interest in the company, and immediately began the most labor friendly mine operation in the United States. She went on to be a top assistant to Franklin Delano Roosevelt's Secretary of Labor, Frances Perkins. Back in Lafayette, life became much better for the coal miners with the more Labor-friendly management of the RMFC.
Coal mining declined as an industry by the 1950s as natural gas replaced coal. The Black Diamond mine closed in 1956 and Lafayette returned to an agricultural economy. As Denver, CO and Boulder, CO grew residential growth in Lafayette increased. With the increase in residential growth the farm based economy changed commercial, small industrial and manufacturing.
Today, Lafayette is a thriving community, with the cultural and commercial center still being found in the revitalized Old Town district, especially along Public Road. The town hosts a variety of unique events each year, including an Oatmeal Festival in cooperation with the Quaker Oats Company, a Peach Festival, a Wine Festival, and Lafayette Days.
The main public high school in Lafayette is Centaurus High School, with approximately 1000 students. The recently opened Peak to Peak Charter School takes students from Kindergarten to High School Graduation. The public middle school is Angevine Middle School, and the elementary schools are Lafayette, Alicia Sanchez, Bernard D. Pat Ryan, and Pioneer Elementary; a bilingual school where English and Spanish are both spoken for half a day. Alexander Dawson School is a K-12 college prep school on the north end of town. Lafayette is part of the Boulder Valley School District.
The mayor of Lafayette is Chris Cameron, and the Mayor Pro-Tem is David Strungis.
There were 8,844 households out of which 37.4% had children under the age of 18 living with them, 52.4% were married couples living together, 10.9% had a female householder with no husband present, and 32.7% were non-families. 22.8% of all households were made up of individuals and 4.4% had someone living alone who was 65 years of age or older. The average household size was 2.62 and the average family size was 3.13.
In the city the population was spread out with 27.5% under the age of 18, 7.5% from 18 to 24, 38.3% from 25 to 44, 20.9% from 45 to 64, and 5.8% who were 65 years of age or older. The median age was 34 years. For every 100 females there were 97.7 males. For every 100 females age 18 and over, there were 95.2 males.
The median income for a household in the city was $56,376, and the median income for a family was $64,088. Males had a median income of $44,167 versus $31,381 for females. The per capita income for the city was $27,780. About 5.2% of families and 7.0% of the population were below the poverty line, including 8.1% of those under age 18 and 9.3% of those age 65 or over.