2017 California Orienteering Week (COW)
2017 California Orienteering Week (COW)

Precision Orienteering (PreO) National Event

Joaquin Miller Park

Date: (Thu.) Mar. 23, 2017
Location: Oakland, CA
Event Director: - 925.872.3935
Course Setter: Nick Corsano
Vetter: Steve Beuerman

Course Setter's Notes

By Nick Corsano

The Bay Area Orienteering Club offers you the rare opportunity to compete in the ultimate test of your map-reading and terrain-interpretation skills: Precision Orienteering, or PreO for short. This is a National Ranking Event for PreO. If you are unfamiliar with PreO, you can read about it here.

Course Specifications

The course follows a paved path. It is marked on the map as a double, solid, black line with brown infill. You are permitted to travel only on this path and the few small branches mapped the same way, except where the "forbidden route" symbol (a purple line across the path) appears. These places will also be marked in the terrain with caution tape. Major dirt hiking trails are mapped with dashed black lines with brown infill​—​these are not permitted routes!

Model Event

Three model controls are set between the assembly area and the Start of the PreO course. The Start is about 0.25 km from the assembly area. The restroom is just before the PreO Start. Be sure to observe the caution tape that separates the area you may use before you start (including access to the restroom) from the area you may use after you start the course.


Bring your e-stick (or borrow one at check-in). We plan to use e-punch, but only for recording official start and finish times. You will manually punch your card to indicate your answer at each control.

Check-in is at the Redwood Glen Picnic Area. You will receive your control card (don't lose it). You may pick up a model-event map, and proceed to the model controls.

Note: In the following, recreational entrants will not have assigned start times; and they will visit, but not complete, the timed controls.

Allow enough time so that you can do the model controls and be at the PreO Start at your assigned start time. Wait at the Start until you are called to the first timed control. After completion of that timed control, the monitor will write your start time on your control card, you will punch the Start unit, and you will pick up your map and proceed with the course.

At the conclusion of the course, you will punch the Finish unit and then wait to be called to the second timed control. When finished there, you will leave your control card and walk back along the same paved path to the assembly area, where you will download your official start and end times, and you can pick up a solution sheet.


We have requested that all the gates be opened in this area on the day of the event. If the main gate onto Skyline Blvd is open, that means you may encounter an occasional car on the path, so be aware. You will more likely run into bicyclists, often in groups. If gates are closed, there are two along the path you will have to walk around. The first is easy to navigate, the second involves a drop off the pavement on one side or a short steep slope on the other. Let us know if you feel you may need assistance.

Map and Terrain

The Joaquin Miller map was redrawn at 1:5000 to ISSOM standards in 2015. The PreO maps are printed at 1:4000 for better readability (especially in the late afternoon light), so symbols will appear a bit larger than standard. This section of the park consists of a combination of redwood forest, mixed forest, and meadows. Typical of Bay Area terrain, there is neither a lot of rock features nor a lot of intricate contour detail, so much of the challenge of the course centers around vegetation. The mapper made liberal use of the distinct-vegetation-boundary symbol (line of small black dots). The model controls should give you a sense of the way the vegetation is mapped.

Here is a rundown of the way certain special symbols are used on the map: