How Airports Serve Colorado
Mark Pearson
This map displays the major airports in and around Colorado. It shows how the state can divided according to which airport is the closest as the crow flies.
The flags are a sample of 500 census tracts (of 1242 tracts total) within the state.
Some census tract flags may look like they are colored for one airport's region but are actually in another airport's region. The census tract flags are colored with which airport they are closest to as the crow flies along the surface of the earth (the Haversine distance formula). The region boundaries that are displayed on map were computed assuming assuming the earth is flat. (The lines that divide regions are a Voronoi diagram, and I couldn't find any algorithm that calculate the lines on a sphere such as the earth.) In short, although a few census tracts may look like they're mislabeled near a boundary, it's actually the boundary that is slightly wrong.
For more information, see the full report:
http://www.mark-pearson.com/airport-distances/

DEN serves 3,442,961 people in CO
Denver International Airport

COS serves 964,436 people in CO
City of Colorado Springs Municipal Airport

GJT serves 225,291 people in CO
Grand Junction Regional Airport (Walker Field)

DRO serves 140,445 people in CO
Durango-La Plata County Airport

EGE serves 128,659 people in CO
Eagle County Regional Airport

ASE serves 83,110 people in CO
Aspen-Pitkin County Airport (Sardy Field)

HDN serves 42,556 people in CO
Yampa Valley Airport (Yampa Valley Regional)

AMA serves 1,738 people in CO
Rick Husband Amarillo International Airport

dividing line

4,843 people
closest airport: DEN

2,301 people
closest airport: DEN

2,583 people
closest airport: DEN

closest airport: COS

closest airport: GJT

closest airport: ASE

closest airport: DRO

912 people

730 people

600 people

closest airport: HDN

closest airport: EGE