It was named after Granby Hillyer,[7] a Denver lawyer who later served as the United States Attorney for that city's district.

Many Granby and Grand County residents are descended from pioneer settlers who arrived before the country was fully surveyed.

Early families established themselves under the Homestead Act of 1862, which allowed easy access to land to those who would inhabit and improve upon the territory.

Marvin Heemeyer was a local auto muffler shop owner who had multiple disputes with the town over zoning, sewage, and other issues.

[9] Several buildings were damaged, including a bank, a hardware store, the concrete company, a utility service center, the town hall, the police department, and a former mayor's home.

[10] The rampage lasted 2 hours and 7 minutes, ending when the bulldozer got stuck attempting to go through the alleyway of Gambles Hardware Store.

[4] This climate type is dominated by the winter season, a long, bitterly cold period with short, clear days, relatively little precipitation mostly in the form of snow, and low humidity.

Granby-Grand County Airport (IATA: GNB, ICAO: KGNB, FAA LID: GNB), a small airport one mile east of town, serves as a stopover for transient general aviation flights, as well as hosts some local aviation activity.

According to the Official Airline Guide (OAG), the airport was previously served by Rocky Mountain Airways which operated scheduled passenger flights to Denver during the mid 1970s with small de Havilland Canada DHC-6 Twin Otter turboprop aircraft.