View from Shell Ridge
 Scenic view from Shell Ridge 
(click for larger image)

Shell Ridge Open Space

(Actually Diablo Foothills Regional Park)

Date: (Sun.) Mar. 4, 2018
Location: Walnut Creek, CA
Event Director:
Course Setter: François Léonard
Type: B; Full-featured, seven-course event for beginners through advanced

Please note that fees and time limits apply. Events are typically not canceled due to bad weather.


The Diablo Foothills event is being moved from Saturday, March 3, to Sunday, March 4.

Despite our best efforts (mainly crossing fingers and hitting refresh on weather websites), the forecast for Saturday is continuing to worsen. With the prospect of thunderstorms, we thought it best not to send runners out along the ridgetops with lightning nearby.

Instead, we'll take our chances with the lingering mud on Sunday. Hopefully most of you will still be able to attend.

In addition to changes on the BAOC website, a message has been posted to the BayONet (, and the Facebook event page ( has been updated, but please help spread the word.

If you are available to volunteer, we could still use help with:

• Beginners Clinics
• Starts
• Control Pickup

March 2018 is shaping up to be a banner month for orienteering in Northern California. Get your legs and map-reading skills tuned up for California Orienteering Week on one of seven courses designed by François Léonard at Diablo Foothills Regional Park. (We're calling this event "Shell Ridge Open Space" because that name is more familiar to most of us.)

Diablo Foothills Regional Park, which encompasses the Castle Rock Regional Recreation Area, is in Walnut Creek, bordering Shell Ridge Open Space and Mount Diablo State Park. Steep oak-studded hills, a winding creek, and views of spectacular rock features await. (A photo of the rock features, as viewed from Shell Ridge, is shown above. You can click on the image to see a larger image.)

The event is open to the public (i.e., to non-members). We encourage everyone to join us. Find out more about orienteering elsewhere on our website.

Location In The Park

Parking will be at the Orchard Staging Area ( This is the same parking lot used at the two previous Shell Ridge BAOC events. (See the directions below.)

The assembly area will be at the Castle Tree Picnic Area (, about an 800-meter walk from the parking lot. Note: This is not the same place we used last year, and there is no parking at the assembly area.

There are toilets at the parking lot, and toilets and water at the Registration/Start area at Castle Tree Picnic Area.

A map of Diablo Foothills Park is available here (PDF/1.6MB) (

What is Orienteering?

An adventure! Discover the outdoors and discover yourself! You can explore a course by yourself or go as a team with your friends. You will get a highly detailed orienteering map, probably unlike any map you have seen before. The map will have a lot of detail on it, such as fences, boulders, lone trees, vegetation boundaries, and anything else you might see. Your course will be printed on the map.

Orienteering is easy to learn, a challenge to master, and incredibly fun!


  9:00 AM – 11:59 AM: Registration open
  9:30 AM – 10:30 AM: Beginners' clinic instruction (free)
 10:00 AM – 12:30 PM: Starts open
           2:00 PM: Courses close, checkpoint control pick-up begins

At registration, all juniors must be accompanied by parents or legal guardians, or bring with them a waiver signed by their parent or legal guardian (the registration form is available here (PDF/100KB)).

Note that you can register and start on courses anytime during the open times above. Thus, for example, you do not need to be "punctual" at 9:00. (You can if you want, but please don't show up earlier and expect to be served.)

Beginners' clinics are short, repeating sessions that introduce the sport of orienteering, and provide enough instruction to be able to complete the beginner (White) course.

Everyone must return to the Finish by 2:00 PM, and check in at E-punch, even if you don't complete your course. We need to account for all participants, because otherwise we must organize a search party for you. At 2:00 PM we will also start taking down controls, so there is no point in staying out longer.


The following fees apply at this event:

  $3 for juniors (age 8 through 20) on beginner's (White) and advanced beginner's (Yellow) courses
  $8 for adults on beginner's and advanced beginner's courses
  $5 for juniors on intermediate (Orange) and advanced (Brown, Green, Red, Blue) courses  
$12 member price for intermediate and advanced courses
$18 non-member price for intermediate and advanced courses
  $1 for a compass rental (optional)  
  $5 for an electronic fingerstick rental (if you don't own one; you'll need one to complete the course)
$15 for the lowest-cost individual one-year BAOC membership (optional)  

Note: We are able to accept payment only by cash or check​—​no credit cards or electronic payments.

For extra people on a team, add $5 per adult on beginners' courses or $7 per adult on intermediate and advanced courses (with lower prices for juniors).

More information about event pricing is available in the club FAQ. All the prices are also shown on the standard entry form (PDF/100KB), which you can print and fill out in advance to save some time at the event. (You will need one entry form for each group of people going on a course together.) Please note that the form has a second page for signatures of group members.

What to Bring

For beginner courses, comfortable outdoors attire and shoes are fine.

For intermediate and advanced courses, leg cover or gaiters are recommended, as well as shoes with some extra grip on the sole.

A compass is not necessary, but can be very helpful. We have compasses available for a $1 rental fee.

We time the courses with the SPORTident system, so each entry/team needs to have a SPORTident fingerstick. If you don't have your own, you can rent one at registration for $5. (Use of the "E-punch" system is easy. You can learn how at the event, or read about it here.)


Here is the course information:

    Course    Length    Climb  Controls
    White     2.7 km    150 m      9  
    Yellow    3.0 km    150 m     11
    Orange    3.1 km    250 m     11
    Brown     2.7 km    225 m     11
    Green     3.6 km    265 m     15
    Red       4.2 km    305 m     14
    Blue      5.1 km    385 m     25

Note that the course Length is simply the sum of the straight-line distances between controls. Your actual distance will be somewhat longer, and will depend on your route choices (and any errors you make). (One rule of thumb is to think "mi" in place of "km"​—​for example, on a "2.7 km" course you might end up covering about 2.7 mi.)

Climb is an estimate of the cumulative "up" that would be encountered on the optimum route, with no regard for any "down" along the way. As with course length, the actual climb you encounter will depend on your route choices (and errors).

More information is provided in the Course Setter's Notes. Be sure to read them.

Request for Volunteers

As usual, we need many volunteers at this event. In particular, we could use a few people for these tasks:

Please contact the Event Director, , to reserve your spot before they're all taken!

Driving Directions

The approximate coordinates of the parking lot are 37.896,-121.997.

Traveling north on I-680: 
Take the Ygnacio Valley Road exit (which is just north of the Hwy 24 interchange). Turn right onto Ygnacio Valley Road and go 2.3 miles to Walnut Avenue (past Walnut Blvd). See below for the continuation from there.
Traveling south on I-680: 
Take the N Main Street exit, and head south on Main St. Turn left onto Ygnacio Valley Road and go to Walnut Avenue (past Walnut Blvd). See below for the continuation from there.
Common to both approaches: 
Turn right onto Walnut Avenue (not Walnut Blvd), and continue 1.5 miles to a roundabout​—​take the first right onto Castle Rock Road. In 1.4 miles you will reach the Orchard Staging Area/Castle Rock Parking lot.

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