⏵ Course guide · Northern California rail-trail
The Bizz Johnson Trail Marathon and 50K follow a USATF certified, net-downhill railroad grade from Westwood to Susanville, California, through the Susan River Canyon and two century-old railroad tunnels. I will walk you through the point-to-point course first, then give you a pacing and fueling plan built for a sustained descent, plus free calculators to dial in your own numbers.
These facts come from the official race website. Check the current year details, start times, and aid stations before you commit. Race logistics change year to year.
All four distances run point-to-point on the Bizz Johnson Trail, the former Fernley and Lassen Branch Line of the Southern Pacific Railroad, built in 1914.
The marathon and 50K begin with an out-and-back on McCoy Road (longer for the 50K, shorter for the marathon), then join the Bizz Johnson Trail proper and climb about 280 feet through the forest to Westwood Junction. From there, it is downhill to the finish in Susanville, with 1,300 feet of descent packed into the final 20 miles, the stretch that makes this course a genuine PR opportunity.
Roughly two-thirds of the way through, the trail drops into the Susan River Canyon, passing orange cliffs and crossing the Susan River ten times on picturesque wooden railroad bridges. About four miles from the finish, you pass through two former railroad tunnels, 800 feet and 450 feet long, a memorable stretch that also means a brief loss of daylight and cell signal.
The 50K and Marathon both bus runners out to Mason Station for an 8:00 AM start. The Express Half Marathon buses out to Goumaz Campground, mile 14 of the full marathon, for a 9:00 AM start, and the new Express 10K buses out to Devil’s Corral for the final 6.2 miles, also at 9:00 AM. Every distance finishes together at Hobo Camp.
A 929-foot net downhill sounds like free speed, but the early climb to Westwood Junction and the accumulated quad fatigue from miles of sustained descent both deserve real respect in your pacing plan.
The roughly 280-foot climb to Westwood Junction comes before the long descent that defines this course, so hold back rather than pushing hard early. A grade-adjusted pace target for that opening stretch keeps you from spending effort you will want on the fast miles ahead.
A net downhill course rewards even effort more than it rewards an aggressive early pace, since the eccentric load of miles of descent adds up fast, especially through the final 20 miles where most of the drop is concentrated. A race-time estimate built from your training on similar downhill-heavy courses gives you a more honest target than a flat marathon PR would suggest.
⏵ Free tools to pace this course
An October morning near Susanville starts cool at elevation and can warm up through the Susan River Canyon, so plan your intake to shift as the miles and the temperature both change.
Aid stations at Westwood Junction, Goumaz Campground, and Devil’s Corral give you regular access on the marathon and 50K routes. Aim for roughly 45 to 75 grams of carbohydrate per hour, and do not let the fast, downhill miles fool you into skipping fuel just because the effort feels easier than a flat course.
Sodium in the 300 to 700 mg per liter range covers most runners, and the Susan River Canyon section can hold heat even on a cool October day, so keep an eye on your intake through that stretch in particular.
⏵ Build your fueling plan
Get a carb, sodium, fluid, and caffeine plan per hour built for your weight, your goal time, and a Northern California October morning with the free ultra fueling calculator. Browse the rest of the free running tools at the tools hub.
⏵ Train for it with Summit Line
Get a race-day plan built around YOUR fitness, this course's net-downhill profile, and your Boston qualifier target. Summit Line reads your real training, builds a plan for sustained descent running, and rehearses your fueling so race day is something you execute, not guess at.
Yes, by design. The USATF certified marathon course (CA18035RS) is a net downhill of 929 feet, following the old Fernley and Lassen Branch Line railroad grade from Westwood down to Susanville. It climbs about 280 feet early to Westwood Junction, then descends the rest of the way, including 1,300 feet over the final 20 miles, which is exactly the kind of sustained net-downhill profile distance runners target for a fast time or a Boston qualifier.
The trail follows the historic Fernley and Lassen Branch Line of the Southern Pacific Railroad, built in 1914, through Lassen National Forest and BLM land. Roughly two-thirds of the way through, the course enters the Susan River Canyon, where you pass orange cliffs and cross the river ten times on picturesque wooden railroad bridges, then pass through two former railroad tunnels, 800 feet and 450 feet long, about four miles from the finish.
This is not a cupless race, though a reusable Speedcup is offered at packet pickup if you want to cut down on waste. With a net downhill profile and distances up to 50K, aim for roughly 45 to 75 grams of carbohydrate per hour, and keep sodium in the 300 to 700 mg per liter range for an October morning that starts cool at elevation near Susanville. Build your numbers with the free ultra fueling calculator before race day.
The 50K and Marathon both start at 8:00 AM at Mason Station after a bus ride to the start, with the 50K adding an out-and-back on McCoy Road before joining the marathon route. The Express Half Marathon starts at 9:00 AM at Goumaz Campground, mile 14 of the full marathon, and the Express 10K starts at 9:00 AM at Devil’s Corral, covering just the final 6.2 miles. All four finish together at Hobo Camp.
You do not drive to your own start line. All four races bus runners out from the Historic Train Depot at 601 Richmond Road in Susanville to their respective starting points: Mason Station for the 50K and Marathon, Goumaz Campground for the Express Half, and Devil’s Corral for the Express 10K. Race packet pickup happens the Saturday before, noon to 6 PM, at the Railroad Depot.
Aid stations sit at Westwood Junction (roughly mile 9 for the marathon, mile 14 for the 50K), Goumaz Campground (mile 14 for the marathon, mile 19 for the 50K, also the Express Half start), and Devil’s Corral on Highway 36 (mile 20 for the marathon, mile 25 for the 50K, also the Express 10K start), spacing that gives every distance real support along the descent.
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<a href="https://runsummitline.com/guides/bizz-johnson-trail-marathon-50k">The Bizz Johnson Trail Marathon & 50K course guide</a><iframe src="https://runsummitline.com/embed/race/bizz-johnson-trail-marathon-50k" style="width:100%;max-width:420px;height:180px;border:0;" loading="lazy" title="Bizz Johnson Trail Marathon & 50K course guide by Summit Line"></iframe>This guide is independent and for planning only. The course details, dates, and aid stations come from public sources and can change year to year, so confirm the current specifics with the official race before you register or run. The fueling and pacing advice is general and not medical advice.
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