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Bon Tempe Reservoir

Greg Ehrensing Memorial Volunteer Event 1

Date: (Sat.) Dec. 6, 2025
Location: Fairfax, CA
Event Director: - 415.456.8118
Course Setter: Dennis Wildfogel
Type: C; Volunteer appreciation event; as in the past, PARTICIPATION IS LIMITED to club members who have volunteered this year; PRE-REGISTRATION IS REQUIRED; NO BEGINNER OR INTERMEDIATE COURSES

Related Event Information

Required Online Registration (https://eventreg.orienteeringusa.org/eventregister/register/start/bontempe2025) Last Year’s Event

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


Advance Notice

This year's Volunteer Appreciation Event at Bon Tempe in Marin will offer something rare in the Bay Area: new terrain to run on! I am in the process of setting courses on an area newly mapped by Bill Cusworth. These courses will be more technical and more runnable than we usually get in our area. There is an area of actual forest (full canopy!) with little undergrowth, and another area that is more open but has a great deal of vegetation detail to navigate by. I am making the courses with as little climbing as possible, though there will be some steeper legs that connect some of the more exciting areas to orienteer in. The longest course will have a steep ascent to near the top of a hill with amazingly scenic views (in case you can get your eyes off the map for a few seconds). All of the courses will require advanced orienteering skills.
More details to come soon — just wanted you all to know what's coming so you can plan for it.
Keep in mind that this event is open only to people who volunteered for BAOC sometime in 2025. If you want to come, but haven't volunteered yet, there's still time. Contact me if you need some ideas. There are no entry fees for this event (but there is a park entrance fee).
Note that this event is on a Saturday.
P.S. If you can't make that date but want to try out the area anyway, I'd be very happy to have some vetting done, or even some "armchair" vetting if you don't want to travel to Bon Tempe.
– Dennis Wildfogel ()
   (Posted to the BayONet (https://groups.io/g/BAOC/message/1868) on Thursday, Oct. 23)


As in the past, this will be our annual, free 2 event to thank BAOC volunteers. All club members who have volunteered in 2025 are invited to attend.

Preregistration is required. You can sign up here (https://eventreg.orienteeringusa.org/eventregister/register/start/bontempe2025) (until 6:00 PM Tuesday, December 2).

Only advanced-level courses will be available. No beginner or intermediate courses will be offered.

Bon Tempe is one of the most scenic orienteering venues in the Bay Area, having a wonderful combination of rolling grassy and openly wooded hills, redwood forests, and multiple water features. Furthermore, forest fire prevention endeavors continue to make Bon Tempe more runnable year after year by removing nasty vegetation and clearing deadfall. The climb is moderate by Bay Area standards, with minimal poison oak, which is easy to avoid. Not being open-range helps as well, both for minimizing mud areas and no barbed wire fences to wriggle under!

The rain we're having in November will make it gorgeous out there.

Preregistration Is Required

If you are eligible to enter this event (i.e., by virtue of having volunteered in some capacity for BAOC during 2025), entry is free (however, there is a park entrance fee). If you are interested (and eligible), but unsure about going, please register anyway. We would rather print a few too many maps, than run out on the day.

You can register here (https://eventreg.orienteeringusa.org/eventregister/register/start/bontempe2025), but no later than 6:00 PM Tuesday, December 2. There will not be registration at the event.

Note: After you register, if you change your mind on the course you want to run, you can change your course selection in the registration system (until registration closes). Do that by clicking the link in the confirmation email you received after registering. If you can't do that, please promptly contact the BAOC Registrar (). There will be a few extra maps at the event for last-minute changes, but the map you want might be gone by the time you arrive.

You can see who's registered here (https://eventreg.orienteeringusa.org/eventregister/reglist/home/bontempe2025).

Schedule

Starts will be from 10 AM until noon on Saturday, December 6th.

Courses will close no later than 1:30 PM. Please make sure you are back at the E-punch table by then.

Notes:
  • Pre-registration is required for this event — sign up will be available closer to the event date. Do not plan to simply show up and run.
  • As stated above, this event is free to all participants. Well, okay, there is an expense​—​there is a park day-use fee of $8.00 per car collected at the park entrance.

Courses

Here are the preliminary course details: 

                                         Physical  
    Course    Length    Climb  Controls  Difficulty
    Mini      1.1 km     10 m      6     Modest    
    Silver    2.1 km     65 m      9     Moderate  
    Brown     3.0 km     95 m     13     Moderate  
    Green     4.1 km    160 m     19     Hard      
    Red       6.0 km    300 m     24     Harder    

All the courses are at an Advanced navigation level.

Holiday Treats

Our Bon Tempe event is usually our North Bay Holiday Season event. If you are so inclined, bring some goodies to share. We'll do our best to get Scott Aster to continue his tradition of bringing his awesome home-made rum cake.

Please consider bringing something to add to the festivities.

Event Location and Facilities

The Assembly Area, parking, and directions are all as they have been for the past few years.

The assembly area will be in the first, small parking lot on the left at the end of the road to the Lake Lagunitas parking lot (see the directions below).

There are restrooms (well, portable toilets) and water near the assembly area.

Driving Directions

Due to MMWD 3 rules, no BAOC directional signs will be posted. There are several ways to get to Bon Tempe from Highway 101 in Marin.

The approximate coordinates for the event are 37.9497,-122.5974. You can use those coordinates, use Google Maps to get directions to "Lake Lagunitas Parking Lot", or take the route described below.

There are several ways to get to Fairfax from Highway 101 in Marin County. The quickest route is to take the Central San Rafael exit (#452, just north of I-580) and turn west at 3rd St (a left at the second light if you're coming from the south, a right at the fourth light if you're coming from the north). Stay on this road for about 3 miles (it changes name three times on the way, eventually becoming Red Hill Ave) until it intersects with Sir Francis Drake Blvd in San Anselmo. Bear right onto Sir Francis Drake Blvd and stay on it until you reach downtown Fairfax.

Turn left at Claus Dr (Rino gas station on the right), and then immediately take another left onto Broadway. Turn right at the next corner (coffee shop on the corner) onto Bolinas Rd.

Stay on Bolinas Rd for 1.5 miles, and turn left onto Sky Oaks Rd​—​that junction is marked by a large, brown, wooden sign on your left with white lettering that says "Lake Lagunitas", "Alpine Lake", and "Bon Tempe Lake". There is also a "Sky Oaks Rd" street sign on the post for the STOP sign for the traffic coming out of Sky Oaks Rd, but that sign is much harder to see than the large sign mentioning the lakes.

Stay on Sky Oaks Rd until you reach the ranger kiosk. If the kiosk is not staffed, pay the $8 entrance fee at the pay-and-display machine 150 m further on the right. The automated pay station accepts debit and credit cards, and $1, $5, and $10 bills, but it does not make change.

Proceed on the paved road to the parking lot at the very end, following any signs to Lake Lagunitas. (Note: Do not turn right onto the gravel road to Bon Tempe Dam.) The assembly area is at the first parking lot you come to in the complex of small parking lots at the end of the road.

_______________

1 We use this event to remember Greg Ehrensing, a dedicated BAOC member, who died in 2018 (at orienteering age 60). Greg particularly enjoyed this event "in his backyard" (since he lived nearby). He directed and course-set this event several times, as well as always helping out at this event and many others with whatever was needed even when he wasn't on the crew that day.
2 There is no event fee, but there is a park day-use fee of $8.00 per car that is collected at the park entrance.
3 MMWD = Marin Municipal Water District