Clo-Cow Half Marathon, 10K & 5K

Sunday, October 15, 2023 • Petaluma, CA • Course Map

Set for its 11th annual running as summer is giving way to fall here in Northern California’s Sonoma County, the Clo-Cow Half Marathon is no ordinary half-marathon. If you’re tired of those boring “flat and fast” halfs, this one is definitely for you.

We take you from historic downtown Petaluma all the way out to some of the great farms of the surrounding Sonoma County, where you will be cheered on by sheep, horses, and of course our beloved “moo-cows.” The trip out there is a challenging one, but the inclines just make the views of those rolling hills even more rewarding.

The course itself starts out with a gradual ascent as you quickly leave the hustle and bustle of downtown Petaluma and head out into the relaxing back-country roads. Instead of cars you’ll hear the cawing of birds, baaing of sheep, and of course Moo-ing of Cows.

Not to mention cheers from our aid stops (seven in total). The hills will be rolling, but the gorgeous greenery that awaits you in the middle miles is worth every foot of elevation gain.

Oh yes, and then you go back down — all those hills you climbed, well, you get to have fun with them on the way home! True, there are undulations on the second half, but gravity will help your tired legs bring you home to downtown Petaluma.

There you’ll of course be treated to some post-race refreshments, but most of all you’ll get your commemorative Clo-Cow Half Marathon Cowbell; that’s a medal you really can’t ignore!

By Alex Wolf-Root, race organizer and president, Empire Runners Club

Race Weather & Climate

While the average temperature hovers in the 60s, early October mornings in Petaluma often start at a cool 50 degrees Fahrenheit, perfect for a half marathon race. The cool weather generally starts with some nice fog, with the sun coming out near midday.

On race day (Oct. 15), the average low is 52ºF and the average high is 82ºF.

Past Results

Course Map

See the race route map for the Clo-Cow Half Marathon here.

Starting Time

  • 7:00 AM – half marathon
  • 7:05 AM – 10K
  • 7:10 AM – 5K


  • $75 – $90 for the half marathon
  • $45 – $65 for the 10K
  • $40 – $45 for the 5K


To reserve your spot in the 2023 running of Petaluma’s Clo-Cow Half Marathon, 10K or 5K race, register online at the official race website below.

Official Race Website

See more races in: October, California

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