Bonanza is a statutory town located in Saguache County, Colorado, United States.

In 1880, Tom Cooke of Salida stumbled upon ore deposits while searching for horses.

Prospectors flocked to this location and the town of Bonanza City was founded.

At the time, population of mining towns was determined by the number of saloons and dance halls instead of a census taker and at this time, Bonanza City had 36 saloons and 7 dance halls.

At the 2020 United States Census, the town had a total area of 280 acres (1.133 km2), all of it land.