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Tilden Regional Park

Date: (Sun.) Feb. 27, 2011
Location: Berkeley, CA
Event Director:
Course Setters: Jonas Kjall, Jim Fish, Angela Hunter
Type: B; Standard seven courses, beginner through advanced

Course Setters' Notes


Here is information about the event from our course setters.


The standard seven courses will be offered at this event. That is, there will be courses appropriate for everyone, from the youngest beginner (around age 8 and above), through endurance athletes to professional orienteers.

The beginner and intermediate courses White, Yellow, and Orange will also be used for the youth courses as part of the COOL series, and will correspond roughly to their Course 1, 2, and 3.

Tilden is a very steep park, making all the courses physically challenging, especially Green, Red, and Blue. The course lengths are stated "as the bird flies", and compares to twice (up to 3 times for the advanced courses) the actual distance. Tilden has surprisingly varied vegetation for being in the Bay Area, adding an extra dimension to the route choices, as well as making it possible for some short technical legs on the advanced courses.

   Course    Length    Climb   Controls   Physicality   Navigation
   White     1.5 km     70 m      13      Low           Very Easy
   Yellow    2.4 km    105 m      14      Low           Easy
   Orange    3.0 km    145 m       9      Medium        Medium
   Brown     3.0 km    125 m      10      Medium        Advanced
   Green     4.2 km    235 m      14      High          Advanced
   Red       5.5 km    365 m      14      Very High     Advanced
   Blue      6.9 km    485 m      20      Very High     Advanced

Both Start and Finish will be at the registration area. E-punch (SPORTident) will be used. (Rental E-sticks will be available at registration.)

White and Yellow

There is an extensive trail network close to the assembly area that the White and Yellow courses will take advantage of. Most of the mapped trails are well traveled and easy to see. Due to the steepness and roughness of the park, some of the trails to be used are not suitable for strollers, but all people who can hike on trails can do the White and Yellow courses.

Due to the many trails in some areas, there are many controls close by, be extra careful when checking that you are at the right one, as well as making sure you are heading off along the correct trail afterward. In the last winter storms, some trees fell down over some trails. I am not sure if they will be cleared before the event. If not, we will put out orange streamers for a route around on the White course. Since fallen trees can sometimes be unstable, a general recommendation is to avoid climbing over (or under) them. The Yellow course will also go around the parking area for Lake Anza. There are hardly any cars here in the winter, but always exercise extra caution when close to traffic. "Out of bounds area", an area forbidden to enter, is printed with red vertical lines on the map.

Orange through Blue

There is no Long-Orange course offered at this event, but we think the endurance athletes who normally like this course should be able to do Brown after they have finished Orange. Brown is more navigational challenging, but it uses the same general area as Orange so the familiarity should make it more comforting when taking a step up to an advanced course. Brown is set with minimizing the physicality as first priority. Green through Blue are set with navigationally challenging as first priority, but there is no unnecessary climb. In fact the slower one moves, the easier the navigation is, and so these two things partly go hand in hand. Contrary to what the stats appear to indicate, we think this year's courses are a little bit less physical than the courses here last year. That said, they are still very physical, so we don't recommend you to move up one course at this event, unless you are really up for a challenge.


As mentioned, Tilden has a lot of trails, is very steep, and has a very varied vegetation. Apart from the extensive areas of dark green and dense undergrowth, the rest is normally very runnable. Even in dark green it can sometimes be possible to find a decent way through if one is lucky, but we think it is very rarely worth trying. Personally we always try to avoid these two vegetation types here at any cost. Many animal tracks and indistinct unmarked "trails" are present that can be beneficiary when found. Most curvature features are very big (hillsides, long reentrants, etc.). Tilden has many black features (boulders and cliffs), as well as small vegetation features, suitable for control locations.


Tilden was mapped in 2006 by the excellent mapper Vladimir Zherdev. It has scale 1:10000 (1:5000 for White and Yellow) and the contour interval is 5 m. The narrow black lines point to magnetic north, and it is 300 m between them. Most of the map is still surprisingly good, but some of the vegetation has started to change. Also, some of the indistinct trails are about to disappear (and some new ones are under way). We have done a fair amount of map corrections, mostly where we think it is a fairness issue (like in picking route choice), but we have still likely missed some we should have made. Since none of us is a mapper we have wanted to keep them to a minimum.


Orange and the advanced courses cross the narrow, winding, and heavily trafficked Wildcat Canyon road twice, so be very careful when crossing! Tilden is used as a recreational park for many people living in Berkeley and the Bay Area, so you will most likely see many non-orienteers when you are on your course — be nice! There is a fair amount of poison oak in Tilden; it will still be winter, so the leaves are not completely out making it harder to spot, but it is also not as strong. If you are sensitive, be extra cautious and bring Tecnu just in case. There are a lot of ticks at this time of year in Tilden, so do a careful body search after the event before or after showering. The tick that carries Lyme disease is indigenous to Tilden, so look carefully, as this tick is very small, about the size of a pin head. Also, if you notice a target shaped rash in the following two weeks, be sure to consult a physician, as this may be the first manifestation of Lyme disease.


The Orange through Blue courses will have one control with water after about 1.3 km. The Green through Blue courses will have another control with water with 1.4–2.0 km left on the course. Red and Blue will also pass through an area in the middle of the courses with many water fountains, some mapped as a blue circle and some at restrooms, mapped as a building. We have only checked a few, but those we have checked will be printed with a red cup on the map.

Course Setters

Jonas Kjall, Jim Fish, and Angela Hunter are the course setting team who has worked together designing the courses. Jonas was the overall course designer and coordinator, and was the main course setter for the two beginning courses and three advanced courses. Jim was the main course setter for the Orange and Brown course, and Angela started the process of learning course design.