Marin’s Trail King: Profile of a Trail Builder

“The hardest thing about trail building is getting permission.” So says Jim Jacobson of Forest Knolls, CA. And he should know. Jacobson has been building trail in these parts for more than 30 years and is responsible for Tamarancho, Big Rock Ridge, Endor (flow trail at Tamarancho), and many of the trails at China Camp …

The Sweco in action. Photo by Tom Boss.
The Sweco in action. Photo by Tom Boss.

“The hardest thing about trail building is getting permission.” So says Jim Jacobson of Forest Knolls, CA. And he should know. Jacobson has been building trail in these parts for more than 30 years and is responsible for Tamarancho, Big Rock Ridge, Endor (flow trail at Tamarancho), and many of the trails at China Camp State Park, a staple for Marin riders. He has advised on too many more to mention.

Though he’s lived in the same house in the tiny hamlet of Forest Knolls (population 1,819 per the 2010 census) since 1970, Jacobson grew up across the way in the East Bay community of Orinda.  “When I was a kid in Orinda, there were four times less people living in California,” said Jacobson. That this is one of the first things he tells me as we sit down for a beer at the Paper Mill Saloon on a rainy Sunday starts to paint a picture. While certainly no hermit, one probably won’t find him opting for city life anytime soon.  While forestry school at UC Berkeley didn’t suit him, it did teach him surveying, which led to work for a time, and would prove useful in his later pursuits.

Jacobson first took to mountain biking in 1984. By this time he was in construction and a ranger friend who patrolled China Camp on horseback entreated him to help build some new trail.

“Pat Robbards wanted to expand the trail system, and he wanted to see the trails used by everyone—horses, hikers, and bikers. He really believed in the multi-use thing,” said Jacobson.

So Jacobson and some pals got busy. With some hard work and perseverance, they built a half-mile of trail in two years. Slow going, to be sure.

“Then this guy shows up with a tiny tractor, specifically designed for building trail, and he cuts in a half-mile of trail in one day, and with volunteers doing finish work by hand, the thing is done with two more days. Three days versus two years. I was impressed,” said Jacobson.

Jacobson on the job. Photo by Tom Boss.
Jacobson on the job. Photo by Tom Boss.

The tiny tractor in question was called the Sweco. Its diminutive stature (the blade is 48 inches across, 85 horses, and the whole thing is 13 feet nose to tail) allows it to operate where larger equipment cannot—a little 9,000-pound trail building fairy dancing through the woods, across hilltops, and through valleys. Jacobson leased one for a month, then finally purchased one in 2003. By this time, the phone was ringing more often with offers of trail building work, and not just in Marin. Jacobson’s reputation picked up steam and respect after the construction of the 10-mile Tamarancho loop on 480 acres of Boy Scouts of America property just outside Fairfax.

“The neighbors wanted to hike on the property, so the Boy Scouts set up a registration process. Then we approached them with time, expertise, and some funds to build a system for bikes, and their leadership at the time said ‘why not?’” Jacobson gathered a crew together and got busy planning, building, and shaping the trail. As evidenced by its top five location (in California) on the esteemed database, people far and wide love this trail. The meadows and creeks, and iris, bay, redwood and madrone forests one passes through in relatively short order feel like a condensed, brightly-illustrated version of California itself. My complements to the trail builder are reluctantly accepted, but Jacobson says not everyone appreciates his work.

“A lot of folks complain that Tamarancho is too tame, but you have to work with the terrain you are given,” said Jacobson. “With any terrain, any trail, the main point is to keep water off and riders on.”

I asked what he thinks about the proliferation of bootleg trails, the fact that everyone these days thinks they’re a goddamned trail builder. Nurse practitioners, IT dudes, high school students, no doubt led to this life of high crime by the lack of legitimate access to trails, have hacked some real shiners into the sides of hills all across Marin (and beyond).

“10% of the trail takes 90% of the work. Folks will get to a hard bit–rock outcropping or other natural barrie–and will just sleeze it in, then it becomes a section that’s destined to fail,” said Jacobson. “Plus, the clandestine nature of what they’re doing won’t lead to the optimal routing since they’re presumably trying to not get caught.”

Sweet Tamarancho singletrack. Photo: Greg Heil
Sweet Tamarancho singletrack. Photo: Greg Heil

“You have to work with the terrain you are given.” One such terrain was the rolling hills outside Petaluma (Sonoma County) where a wealthy landowner wanted to build a trail system on his property for the express purpose of hosting a NorCal NICA race. This type of work is clearly what Jacobson enjoys most these days—private clients, private property, bike-specific. While the bureaucracy of public lands and their various minders are a frustration, they still pay some of the bills. Jacobson says that his current mix is about 2/3 private, 1/3 public. And while change is excruciatingly slow here in Marin County, some progress is being made via the County’s Road and Trail Management Plan process. To Jacobson, the language in it allows much, but took too long to produce and delayed opening new bike trails for several years. While a vocal minority of hikers, equestrians, and old-school conservation groups threaten to sue the County any time a bike-legal trail is proposed, spines appear to be stiffening at last. As a result of that protracted process, several trails in Marin County’s Open Space lands are set to open to bikes this year.

Jim Jacobson gives several impressions at once: mild and friendly to be sure, but rigid and resolute in many of his assessments. When he informs you, as he will, that something is stupid, he’s got the gravitas to make you wonder how you ever thought it could be otherwise. And yet, when describing the work of younger trail builders and new ways of doing things, a refreshing openness and respect graces his statements.

“Zachie Anderson with Forest Trails Alliance does it differently. He cuts trail and then backfills behind him so it looks like the trail has been in longer. Most folks cut and cast off. He’s putting together a good crew, training folks how to do this work,” said Jacobson

At 70 years old, you’ll find Jacobson behind the wheel of his Sweco more often these days than atop the wheels of his mountain bike, owing to “old age and decrepitness.” Self-effacing comments aside, a life way from the masses deep in the grasp of one forest or another has done him well–I doubt that anybody would guess his age at much over 50. However, if Marin’s Trail King feels the need to choose between riding trails and building them, it is surely our collective good fortune that he and his tiny tractor opt for the latter. If only there were some kind of technological advance that would make it possible for a life-long devotee of mountain biking to continue to enjoy the many trails he’s built and maintained over the years…

A rider enjoys the work of trailbuilder Jim Jacobson on Tamarancho’s flow trail, Endor.

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