Denver streets set for rolling closures Sunday as runners celebrate 20 years of the Colfax Marathon

The Colfax Marathon is this weekend, which means there will be some delays and closures on Denver streets as runners work their way through the 26.2-mile course. Riders using an RTD bus or train will see delays and changes on Sunday.

D, H and L light rail

• D and H lines will not serve Colfax at Auraria Station through the Downtown Loop stations on Stout and California streets 
• D and H lines will continue to serve 10th-Osage Station, and will reroute to serve Auraria West Station, Empower Field at Mile High Station, Ball Arena-Elitch Gardens Station and Union Station 
• The L Line will not be in service during the event, and customers are encouraged to use bus Route 43 as an alternative 
• No impacts to RTD rail service are expected to occur on Saturday, May 16 
• Customers should expect delays on D, E, H and W lines during the event due to increased rail traffic at Union Station. Plan for extra travel time to/from Downtown 

Bus routes: 

• May 16 only: routes 20 and 24 will have a minor detour around the event, 9 a.m.-noon during the Colfax 5K race  
• May 17 only: the following bus routes will be temporarily detoured in many areas, and will be allowed to cross the marathon route when possible: 0, 1, 6, 8, 9, 10, 12, 15, 15L, 16, 19, 20, 24, 28, 30, 38, 40, 43, 44, 48, 51, 52, 76, 83L, ART, FREE 

For the May 17 race day, RTD is accepting Colfax Marathon 2026 race bibs, 6 a.m. to 2 p.m. as valid fare payment on the following rail lines and bus routes: 

• Rail lines: W Line 
• Bus routes: 15, 15L, 16 

The courses run through Denver and Lakewood on May 17.  Road closures are between 5 a.m. and 1 p.m. depending on the part of the city. This includes: 

Traveling north/south

• I-25 will be open
• On the east Colorado Blvd will be open (except southbound from 29th to 17th), and all roads east of Colorado Blvd.
• To the west Kipling will be open, and all roads west of Kipling.

Traveling east/west

• In general stay south of Colfax (14th and lower) and north of 29th (30th and higher).

The Colfax Marathon said the road closures are rolling closures and will reopen after the last runner.