Ralston Creek Half-Marathon
& 5K Run

February 18, 2018
Arvada, Colorado

The Ralston Creek Half Marathon and 5K returns in 2018, after sold out fields in the half for the past 6 years! Join us at Colorado's Premier Winter Half Marathon, and the finale to the 2017-2018 Racing Underground winter running series.

The Ralston Creek races feature a fun winter half-marathon and 5K run conveniently located on the west side of the Denver Metro Area in Arvada, Colorado. The courses covers a scenic mix of road and bike path over rolling terrain, and an optional early start time for half-marathon runners who expect to take more than 2.5 hours to complete the course!


HALF-MARATHON COURSE:The Ralston Creek Half Marathon course follows a mix of roads and bike paths on the west side of Arvada. The opening 5 miles are fairly flat, with a barely noticeable gradual gain in elevation. Miles 5 through 6.5 are rolling, with one good climb leading to the high-point of the course atop Ralston Mesa at 7.75 miles. From there, the course is almost all downhill and flat to the finish, with the exception of a small bump around mile 9 and a very gradual uphill in the last half-mile. Click Here for a Half-Marathon Course Map

Half-Marathon aid stations are located approximately every two miles throughout the course (approximate locations are: 2.25, 4.25, 5.75, 7.25, 9.5, 11.5) All aid stations will have both water and Gatorade Endurance energy drink. Hammer Gel will be available at miles 4.25 and 9.5.

5K COURSE:The Ralston Creek 5K Run course follows a mix of roads and bike paths on the west side of Arvada. The route starts with a slight downhill in the opening mile, a flat second mile, and a very gradual uphill in the final mile. A single aid station will be located at approximately halfway into the 5K run. Click Here for a 5K Course Map


The Ralston Creek Half Marathon and 5K will offer a three wave start. Wave-1 will start at 9:00am for half-marathon runners who plan to take longer than 2.5 hours to complete the course. Wave-2 will start at 9:45am for half-marathon runners who plan to take less than 2.5 hours to complete the course. Wave-3 will start at 10:00am for all 5K runners.

This start procedure is designed to improve the finish line and post-race experience for the slower runners. The 45 minute gap in start times will allow the wave-1 runners time to spread out on the course before the faster runners begin. This start procedure is a runner favorite! Please be aware: runners starting in wave-1 who finish the race faster than 2:15 will be removed from the results and disqualified. Wave starts are timed so returning wave-1 runners and outbound wave-2 runners do not have to share the path. Please select the appropriate wave for your ability level. If you are not sure, please select wave-2.

A 2:30 half marathon time is roughly an 11-minute and 30 seconds per mile pace.

  • 7:30 a.m. - Packet Pick-Up Opens
  • 9:00 a.m. - Wave-1 Start (half-marathon runners expecting to take more than 2.5 hours)
  • 9:45 a.m. - Wave-2 Start (half-marathon runners expecting to take less than 2.5 hours)
  • 10:00 a.m. - Wave-3 Start (all 5K runners)
  • 11:00 a.m. - 5K Awards Presentation*
  • 11:30 - Half-Marathon Top-3 Overall Awards Presentation*

  • Overall Awards will be based on GUN TIME

  • Half-Marathon Age-Group Awards will be based on NET TIME, and will be presented in several ceremonies, on a rolling basis after 11:30 as award categories fill. You may also opt to skip the awards presentation, and simply stop by the awards tent to pick up your age group award if awards for your category have been confirmed. The awards tent will receive updated awards lists throughout the morning.

  • Raffle prizes will be presented at the finish line to random finishers. It is winter, after all! We're not going to ask you to wait around to see if you won something!

*Awards for overall top-3 will be determined by GUN TIME for both the 5K and the half marathon. Age Group awards for both races will be based on NET TIME. The scheduled time for the awards presentation may be moved a bit depending on weather and number of athletes still on course

INFORMATION: Most questions are answered right here on the race website. If you have a question that isn't answered here, call Darrin or Jill at 303-642-7917, or shoot us an email at darrin@racingunderground.com


Half-Marathon entry is limited to the first 650 registrations. 5K registration is limited to the first 750 entries. Once a distance has filled, we cannot accept any additional entries.

Your entry fee includes entry into the race, a finisher's medal (for half-marathon runners who complete the course), FREE race photo downloads, fun music, a racer goody bag, hot cocoa and tasty post-race food, entry into our sponsor merchandise drawing, and if you are one of the speedy guys or gals up front in the half-marathon, you may take home a bit of cash!!!

A long sleeve half-zip race tech shirt will be included with all adult entries received before January 19th. Entries received January 19th or later will include a long sleeve race tech shirt. Youth 5k entries will include a long sleeve 50/50 t-shirt.

Click button below to register (Online Registration will close at noon on Saturday February 17th)

Click button to register
online for Ralston Creek
or the Entire Series

Click Here
to print & Mail
your entry

ENTRY FEES: Ralston Creek 5k or Half