Question 1

How many marathons in Colorado are there in 2027?

Accepted Answer

There are 6 upcoming marathons in Colorado listed on 42Cal, from May 2027 through October 2027. The count updates automatically as races are added.

Question 2

When is the best time for marathons in Colorado?

Accepted Answer

Most of the 6 races on this list (4 of them) fall in May and October 2027.

Question 3

Which race in this list has the least elevation gain?

Accepted Answer

Colorado Springs Marathon in Colorado Springs is the flattest race on this list, with about 492 ft of total elevation gain — based on the 6 of 6 races here with elevation data on file.

Question 4

How current is this list?

Accepted Answer

This list was last refreshed on November 14, 2026. Race dates, locations, and course details are updated continuously as organizers confirm changes, so this page reflects the calendar as of that date.

Race	Date	Location	Distance	Elevation	Status
Colorado Marathon	May 2027	Fort Collins, United States	Marathon	180 m	Registration Open
Colfax Marathon	May 2027	Denver, United States	Marathon	211 m	Registration Open
Steamboat Marathon	June 2027	Steamboat Springs, United States	Marathon	736 ft	Registration Open
Boulderthon	September 2027	Boulder, United States	Marathon	603 ft	Registration Open
Colorado Springs Marathon	October 2027	Colorado Springs, United States	Marathon	150 m	Registration Open
Windsor Marathon	October 2027	Windsor, United States	Marathon	250 m	Registration Open

Marathons in Colorado 2027

Upcoming Marathons in Colorado 2027

Colorado Marathon

Colfax Marathon

Steamboat Marathon

Boulderthon

Colorado Springs Marathon

Windsor Marathon

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