Bon Tempe Reservoir
Greg Ehrensing Memorial Event for BAOC Volunteers
Date: (Sat.) Dec. 2, 2023
Location: Fairfax, CA
Event Director: 
- 415.456.8118
Course Setter: Dennis Wildfogel
Type: C; ONLY ON SATURDAY this time; as in the past, participation is limited to only club members who have volunteered this year; PRE-REGISTRATION IS REQUIRED; NO BEGINNER OR INTERMEDIATE COURSES
Related Event Information
Course Setter’s Notes
By Dennis Wildfogel
The courses for December 2 (Saturday!) have longer legs and generally emphasize route choice. Forest-fire mitigation work has made many areas of the park more passable. The map is more accurate than it has ever been. The ground is quite runnable. In short, conditions are excellent.
Here are the course details:
Course Length Climb Controls
Short Brown 2.7 km 125 m 7
Brown 3.6 km 175 m 10
Green 5.5 km 275 m 13
Red 6.8 km 340 m 17
The map scale is 1:7,500 for all the courses. The contour interval is 5 meters.
All courses have water stops roughly every 2.5 km.
On the Red course, lines connecting consecutive controls sometimes criss-cross one another, and sometimes even go through other control circles. Be sure you identify which control you are actually supposed to go to next.
There is a large junk yard near the Finish. This area is Out Of Bounds and is marked with red cross-hatching. You must not go through this junk yard — go around either side. The red line from the last control to the Finish goes through this area, and so is rather difficult to see because of the red cross-hatching.
If you happen to be the first competitor to get to a given control, that control may not have been awoken yet. That means it won’t respond to an SI Air stick unless you insert the stick into the control unit. Doing so will awaken the control for everyone else (thank you).
One of the control features on some of the courses looks like a hot water heater standing in the middle of the woods. On the map, this is denoted by a square with a blue perimeter (ISOM 2017-2 symbol 311, “Well, fountain or water tankâ€); on the clue sheet, it is a horizontal box with a wavy line above it (IOF Ref. 3.11 “Water tank, Water troughâ€).
Note: The current International Specification for Orienteering Maps, ISOM 2017-2, can be found on the BAOC website here (1MB PDF). The International Specification for Control Descriptions (with graphic examples) can be found here (3.1MB PDF).
Map
Solid black lines forming a closed loop are stands of redwood trees. The shape on the map represents the boundary of the stand of trees. There are many such stands on the infamous Hillside of Death (which, if you are not familiar with it, you can recognize on the map by virtue of it being the one place where there are many such stands). These stands are very valuable for navigation. All the courses have one or two such stands as control locations. The control description is a circle (IOF Ref. 6.2, “Prominent feature/Special itemâ€). NOTE: In each case, there is more than one such stand inside the control circle, and I neglected to add “southern†to the control description. My apologies.
There are several small patches of ISOM 2017-2 symbol 404, “Rough open land with scattered treesâ€. This symbol is a pale yellow background with a regular pattern of white dots (scattered trees) or green dots (scattered bushes/thickets). These patches can be hard to recognize on the map because they are so small that one might not immediately recognize the “regularity†of the dot pattern, leading one to imagine that the dots represent individual objects. The white dot pattern is used for an area with several small trees without canopy; the green-dot pattern is used for an area with numerous bushes, too diffuse (and, therefore, easy to run through) to call a thicket, but distinct enough in the surrounding bush-less terrain to warrant being placed on the map. Note that single, solitary bushes are not mapped at Bon Tempe: any small, individual green-dot-with-white-center on the map (ISOM 2017-2 symbol 418, “Prominent bush or treeâ€) always represents a small tree.
There are quite a few prominent standing dead trees in the terrain and on the map. These are sometimes “snags†(i.e., a large trunk with no limbs or crown, presumably from a lightening strike) or, more often, a tree that looks like it died from disease and still having many limbs and branches). Both of these are represented by green ×’s on the map (ISOM 2017-2 symbol 419, “Prominent vegetation featureâ€). When used as a control, the description is IOF Ref. 4.9, “Prominent tree†(a simplistic child’s drawing of a tree) with the appearance (Column E) qualifier IOF Ref. 8.11 “ruinedâ€. This qualifier is drawn as an arrow bending over, and usually denotes something that has fallen to the ground, but not in our case: we are using it to mean “dead†but standing.
Almost all the earth banks indicated on the map are passable. In a couple of cases, where an earth bank exists because of a road below it, you might be wise to move along the earth bank until you find a better place to climb or descend. Some earth banks that were created when a road was constructed are not on the map.
As with most maps, there are more root stocks in the terrain than are on the map. Furthermore, some of the older root stocks, while still distinct, no longer show much in the way of roots. Any root stocks used as control locations are very visible in the terrain. The symbol used for a root stock on this map is a small, brown triangle.
There are a few very distinct animal trails that are not on the map.
Terrain
There are two “networks†of gullies that you might come across (only one on Short Brown). In each case, it’s just two gullies that at some point combine into one, and in each case the upper ends of the two gullies are shallow and are mapped as ditches. The map symbol for a gully is a thick brown line, which in appearance looks exactly like an index contour — and that is what I want to alert you to: in both cases, you might think you’re looking at an index contour, not a gully. All I can say is look at your map carefully if you see an extended, thick, brown line that is not obviously parallel to nearby contour lines. One of those systems is not far from the assembly area, and is easy to cross (except where it is clogged by vegetation); the other is much further north, and is difficult to cross (you’re better off going around). By the way, there are a couple of other short gullies that you will encounter, but those should be easy to identify on the map as they are obviously perpendicular to the nearby contour lines.
I’ve noticed some newly fallen trees in the last week, including one across a popular walking trail. You can easily get around the ones I saw, but you might wonder why they’re not on the map.
Hazards
Watch out for cars and bicycles when you cross Sky Oaks Road (the paved road that you drive in on, and the only paved road on the map). In particular, bicycles often go very fast on the one downhill section of Sky Oaks Rd, so be very alert when you cross there, as the lines of sight are not very good. There can also be cars and bikes on a gravel road that 'Red and Green have to cross, but traffic moves much more slowly on that gravel, and also lines of sight are good.
Cleated shoes with metal tips are recommended, but if you don’t have shoes like that, at least wear rubber cleats.
Rocks and fallen logs can be slippery, even if they don’t appear to be wet. Try hard not to step on a fallen log.
I haven’t found any ticks on me after being out at Bon Tempe, but the other day a park ranger took it upon herself to tell me (as I ran by) that tick season is just beginning.
The thorns and stickers are not bad at all, but they are out there. If you don’t want to spend time after the event picking things out of your socks, you might consider wearing gaiters. (Note added Thursday, Nov 30: hanging controls today, came back with hardly any stickers. Recent rain must've helped!)
The only large animals in the park are deer, who will generally run the other way if you get near them.