The Hills Have Eyes

(TrailCross Black Diamond)

Black Diamond Mines Regional Preserve

Date: (Sun.) Mar. 24, 2013
Location: Antioch, CA
Event Director:
Course Setters: Terri Hunt, Kevin Hinkley
Type: C; 5 km, 10 km, and 10-mile trail runs with twists! Find your way with a map.

Club members, please note that this event has non-standard event ( and fee ( schedules. Time limit ( applies. Events are typically not canceled due to bad weather.

Enjoy a fun 5 km, 10 km, or 10-mile romp in the scenic hills of Black Diamond Mines! Grass will be green and ground, soft. Views will be out to the Bay in several directions, and all the way to Mount Diablo ... but you have to earn them! Trails are quite steep in this park. Are you up to the challenge?

About TrailCross Black Diamond

This will be BAOC's first-ever TrailCross event, a new format for trail runs and for orienteering. It's like a trail run, with aid stations and prescribed distances. Here's the twist: you will get a map with the course on it — you need to find the checkpoints marked on the map, which are located on or near trails. Taking the trail, of course, is optional if you'd like to try a shortcut or two!

Be sure to read the Event Director's Notes below for more information.

What's It Like?

Have you mastered the trails ... but always wondered what it's like to go off-trail, cross country? To run free ... set your own path through the grasses, through the trees ... take a shortcut to the summit and get there ahead of the rest?

With TrailCross, you can!

Trails will not be marked for this event. Take whichever one you think is fastest! The course will consist of a series of checkpoints; about one every kilometer on the 5 km and 10 km courses, about one every mile on the 10-mile course. Checkpoints — and all trails, and elevation lines — will be shown on your map. Most checkpoints will be on trails or visible from trails; a select few will be on topographical features, such as hilltops and saddles.

At each checkpoint, there will be a marker and an electronic station to record your visit. You must visit these checkpoints in order to record an official race time. Most checkpoints won't be manned; however, several will feature fully stocked aid stations.

There will be a single aid station on the 5 km and the 10 km courses, and two aid stations on the 10-mile course. Plus, enjoy a cornucopia of tasty snacks at the Finish!

Do I need to be an expert navigator to run TrailCross?

No. The course is intended for runners who are comfortable with trails, and want to take the next step. It helps to know how to read a trail map. If you can't, it's perfectly fair game to follow someone else.

Will I get lost?

Unlikely. In case you are, find your way to the nearest trail ... facing the unexpected is part of the challenge!


This is a mass-start event, so be on time! The Start will be less than a mile away from the parking and Finish — this allows us to create the best challenge. We will run shuttles to the Start, or you are more than welcome to take a warm-up jog.


These details are preliminary and are subject to change.

   Course      Distance     Climb   Checkpoints
   Long        16.1 km      600 m       13
   Medium      10.0 km      395 m        9
   Short        5.0 km      165 m        7

Aid Stations

One fully stocked aid station on the 5 km and 10 km courses, two on the 10-mile course. Aid stations will feature candy, chips, energy bars or energy gels, pastries, water, and a sports drink.

Photo gallery image (click to enlarge)

Shirts and Awards

A technical TrailCross Series T-shirt is offered with the registration for a nominal fee.

We will award the top male and female runner for each of the three distances, plus the top Masters (40 years of age and over) and Junior (20 years and younger) runners of each gender.

More Details


Participants will be responsible for their own safety while taking part. Of course, event staff will try to help you if we learn that you are seriously injured or otherwise need assistance, but there is a good chance you would be waiting a long time for help, and we don't have the level of staffing or expertise necessary to quickly and expertly handle many emergency situations that might arise, so your best bet is to be very careful not to get injured. If you are not comfortable assuming the risks involved in prolonged exertion while traveling through rugged terrain under various and possibly unexpected conditions, then you should not take part in this event.

We will have a certified EMT at the Finish. The EMT can reach participants on the course, but is not authorized to transport them out.

Time Limit

There is a 4.5-hour time limit for all courses. We will not allow 10-mile course participants to continue after their second aid station if we think they won't make it to the Finish before the course closure.


Each runner will be given a map at the Start. A recent copy of the map will also be available at check-in, but it will not have today's course on it.

You should carry a bottle or other container that can hold at least 0.5 liters (a pint) of water. It can get quite hot at Black Diamond, even in March, so a water bottle will help keep you hydrated between aid stations. You are required to carry a whistle for emergency signaling — you can get one for free at check-in.

Shoes with good traction will help. Although "proper orienteers" often wear special clothing that can protect them if they intend to bash through unpleasant vegetation, no such bashing is expected at this TrailCross — you'll either be on trail, or going through beautiful grassy meadows. Dress as you would for a trail run, plus perhaps gaiters or calf sleeves to cover your lower legs.

The race is electronically timed with SPORTident equipment. We will have SPORTident electronic tags available (the price of the rental is included in your entry fee). If you own one, you are welcome to bring and use it! A compass is useful, but not necessary. We have compasses to lend, also included in your entry fee.

There is cellphone coverage at Black Diamond Mines, but the hills block the signal in the valleys. You are almost guaranteed to get a signal on ridge tops, very likely voice and SMS, possibly also data.

To cover all bases, you may wish to bring a watch so that you know how fast you are going, some salt tablets (especially if you plan to be out for longer than 3 hours), and a space blanket (last year it got pretty chilly). GPS is allowed, as are altimeters and any and all additional navigational aids that you desire.

The Course and Checkpoints

Courses for this event will not be published in advance. You will learn the course at the Start.

Generally, each checkpoint will feature route choices. You can either take a trail the whole way, or part of the way, or cut straight. Several checkpoints will feature a choice of several trails. It's OK to follow someone, but beware that they may not have the best route! They might even be lost!

The published course distance is measured along what the course designer thinks is the optimum route. It is the distance that the winner is most likely to cover. You may cover slightly less or a lot more, depending on your choices.

We are explicitly allowed to travel off-trail at this event at Black Diamond Mines (and at our other venues). Although park rules generally require that users stick to trails, several park districts in the Bay Area allow cow grazing, and a single cow is guaranteed to generate more impact than perhaps all of our TrailCross participants!

However, certain areas of Black Diamond Mines do not allow off-trail travel, because they harbor sensitive plants and animals. These areas will be marked on your map, and anyone traveling through these areas will not get credit for the course. All of the sensitive areas are overgrown with chaparral, which makes cross-country travel very slow, difficult, or impossible; rest assured that you can't just venture there by mistake and trample upon the sensitive plants. You can still take the trails that go through these areas, just don't try to shortcut.

Still have questions?

There is an FAQ on the TrailCross Series page. You are also welcome to contact the via email.



                           Regular       Event-Day 
                        (before or on   (on or after
   Course   Category      Wed 03/20)     Thur 03/21)
   10 mi    Adult            $28            $33
            Junior (*)       $8             $8
   10 km    Adult            $23            $28
            Junior (*)       $5             $5
    5 km    Adult            $18            $23
            Junior (*)       $3             $3
   (*) Juniors are age 20 and younger.

Member of BAOC, GCO, or any other Orienteering USA club

                           Regular       Event-Day 
                        (before or on   (on or after
   Course   Category      Wed 03/20)     Thur 03/21)
   10 mi    Adult            $23            $28
            Junior (*)       $8             $8
   10 km    Adult            $18            $23
            Junior (*)       $5             $5
    5 km    Adult            $13            $18
            Junior (*)       $3             $3
   (*) Juniors are age 20 and younger.

Technical, short-sleeve TrailCross Series shirts are $7. They can only be obtained with event registration. SPORTident electronic tag (and compass) rental is included in these fees.


Please preregister to help us plan for the event, so we can get the right amount of maps and supplies. Secure registration is open through Event Register by Orienteering USA ( (As of February 20, the registration page is functioning and accepts online payments.)

Note that preregistration is not required — you will be welcome at the event even if you haven't preregistered, except in the unlikely event of a sellout.

Driving Directions

Black Diamond is located in Contra Costa County, south of Pittsburg and Antioch. Take Highway 4 to the Somersville Road exit in Antioch, then drive south (toward the hills) on Somersville Road to the Preserve entrance. We will be using the first parking lot on your left.

There's a map here that shows the location of the event.

Public Transit

Buses run often in the Delta, and come to within 3 km of the event's parking and Finish, but are slow as snails. Your best bet is to take BART ( to Pittsburg/Bay Point station, and then carpool with fellow runners or cab it. Please email the if you need help arranging transportation to the event.

Event Director's Notes


Welcome to the inaugural TrailCross! We are super excited to join you this coming Sunday on the trails of Black Diamond Mines Regional Preserve.

If you have registered, but haven't paid, we will gladly accept payment at check-in.

Photo gallery image (click to enlarge)

T-shirts are on their way and the design is shown at the right.

Here are a few reminders and other information:

Please don't hesitate to check this page for information, or to contact if you have any questions.

See you soon,

Vladimir (Event Director)
Kevin and Terri (Course Designers)
Rex (BAOC Events)