We knew Colorado was growing, but we didn't know it was like this.

Seven Colorado cities ranked among the 50 fastest growing cities in America with Longmont, Colorado leading the pack at number 1.

Longmont, along with Greeley and Denver were among the top ten, Greeley was ranked 5th and Denver 7th among the top 50. SmartAsset put the list together to show how fast cities are growing in America.

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Greeley, according to the study doubled the average growth rate for most of the cities on the list. The website used population change, unemployment rate, change in the unemployment rate, GDP growth rate, business growth, housing growth and change in household income to determine the fastest-growing cities.

The top ten were Longmont, Denton, Tx, Mount Pleasant, SC, Miami, Fl., Greeley, New Braunfels, Tx, Denver, Charleston, SC, North Charleston, SC and Round Rock, Tx.

Fort Collins made the list at number 15, Highlands Ranch at 30 and Arvada at 34 with Thornton coming in at number 42.