Driving along the back roads of the 800-acre U.S. Coast Guard Training Center in Two Rock, it doesn't take long for MudMan organizer John Olson to get down to the core of the matter — the art of mixing dirt and water.
"Making mud isn't as easy as you think," he says.
"We had a problem at first with everything falling out of it and you're left with water on top of a sand base.
"But then we figured it out: You've got to keep it churned right up until the competition starts."
He stops his truck and gets out to show off a wide patch of dirt, soon to become one of five massive mud pits competitors will have to slog, tread or swim through to finish the second annual competition of grubby endurance.
Next weekend's MudMan event is Sonoma County's answer to the nationwide trend of MOB (Mud, Obstacles, Beer) events luring a younger generation into the field of endurance sport.
At events such as Tough Mudder, Mudathlon, Dirty Girl and Muddy Buddy, it isn't always about how fast you finish (although bragging rights are a bonus), but that you actually finish at all.
"Most people aren't trying to win. They're here to have fun and for the experience," said Russ Pugh, owner and of Vineman Inc., which stages a handful of world-famous triathlons every year in Sonoma County.
He created MudMan to bring in "a different set of competitors who might never enter a Vineman."
But whereas the super-strenuous Tough Mudder events, described by some as "Iron Man meets Burning Man," involvea 10,000-volt electric-shock obstacle, MudMan is not quite as hardcore.
"We like to call it a family adventure picnic," said Olson.
And finishers only earn one beer at the end, not a limitless flow like some competitions.
Last year's overall champion, Catherine DuBay, a 30-year veteran of 10K runs, triathlons, half-marathons and marathons, had never entered a MOB event before.
"There was a lot more running than challenges," she said.
"In fact, the guys who were in the race with me, who took off like a bat out of hell, at the end when I had beat them pretty handily, they said they had trained extensively in these boot-camp classes and they were shocked that I'd beaten them.
"The difference was that it was basically a 5K with a few stops along the way."
Rising to the challenge, MudMan organizers have loaded up the 3.5-mile course with more mud pits and a larger bungee maze (picture a spider web of elasticity waiting to ensnare you at the top of a hill).
The climbing walls and downhill slip-'n'-slide are back again. And this year, the sound of exploding bombs and gunfire will be piped through speakers around the course.
Organizers chose the sprawling U.S. Coast Guard station west of Petaluma after a colleague introduced them to base officials who were interested in hosting an event that would draw widely from the community.
"They like the positive exposure it brings them and we love all the space," said Pugh. "It's a win-win."
Evolving from Vineman to MudMan, he sees it as the natural progression of the sport, from sweat to mud.