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Shell Ridge Open Space

Date: (Sat.) Sep. 17, 2005
Location: Walnut Creek, CA
Event Director: - 925.926.0853
Course Setter: Rob Clima
Type: B; National Orienteering Day "Come and Try It" event with standard White through Blue courses

This will be a standard event with the full range of courses offered. The standard schedule ( for registration, starts and course closure will be followed. E-punch will be used for Orange and advanced courses. Maps are 1:10000. Poison oak prevalence in the park is low, but if you are very sensitive, please take precautions. A portable toilet will be available near the registration area.

We have been instructed by the park ranger NOT to cross fences. Hence, crossing a fence without using a gate will be an automatic disqualification. The White, Yellow, Orange, Brown, and Green courses do not encounter fences. If you are on these courses and find yourself wanting to cross a fence, think again. On the Red and Blue courses, you will need to cross the fence several times. A control has been set at each of the gates that must be used to cross.

Map quality is generally poor. There are unmapped and extended trails, and some of the existing trails are not mapped precisely. Boulders are not reliable and contours sometimes require interpretation. White "forest" or vegetation boundary is sometimes just a single tree. However, the map quality should not be a problem for this event since orienteering in Shell Ridge is not technically difficult.


You may print and fill out an entry form ( in advance if you wish (which may save time if you are bringing a large group, PDF files are viewable with the free Adobe Acrobat Reader (

Preliminary course statistics (see the Course Setter's Notes for more information):

  Course     Length     Climb     Navigational Challenge
  White      3.4 km     125 m     Beginner
  Yellow     3.5 km     150 m     Advanced Beginner
  Orange     4.0 km     175 m     Intermediate
  Brown      3.1 km     225 m     Advanced
  Green      3.5 km     265 m     Advanced
  Red        5.0 km     350 m     Advanced
  Blue       5.4 km     375 m     Advanced

Anyone interested in volunteering for this event, please contact the Event Director.

Driving Directions

From I-680 in Walnut Creek, exit onto Ygnacio Valley Road, and head east approximately 2.3 miles to Walnut Avenue (NOT Walnut Boulevard). Turn right on Walnut Avenue, and go 1.5 miles to Oak Grove. Turn right onto Oak Grove, and immediately veer right onto Castle Rock Road. Northgate High School is on the right about 0.5 miles along Castle Rock Road. Park in the school lot closest to the hills, past the buildings. Registration and starts will be about a ten-minute walk from the lot along Castle Rock Road, right on Comistas Drive, and left on Hanna Grove Trail.