Bon Tempe Reservoir

Greg Ehrensing Memorial Volunteer Event

Date: Dec. 5 - 6, 2020
Location: Fairfax, CA
Event Director: - 415.456.8118
Course Setter: Dennis Wildfogel

Photo gallery image (click to enlarge)

Running a Course After the Event

You can still run the courses from the December 5/6 Bon Tempe event. Just download and print the two maps for your course (see below for details). The control markers are no longer in the field, but there is a small surveyor flag marking the location of each control. The flags are red, about 2" by 3", and are on thin wire posts about a foot high; the control number is written on the flag. (Note that neither the Start nor the Finish are marked in the field, but their locations should be obvious. Also, the streamers from control #59 to the gully crossing have been removed.)

Of course, you can just go out and run any of the courses on your own. But for a little more excitement, Bill Cusworth has set up the courses for use with the MapRun apps. The MapRunF ( version of the app runs on iPhone and Android phones; MapRunG ( runs on Garmin watches that are capable of loading apps. The app “knows” about the control locations, and when you get within several meters of the control, the app will make your device beep and record your time. When you’re done, the app can automatically upload your track to RouteGadget, if you like. Check out Bill’s instructions below.

Unless we get pressure to remove them, I expect the surveyor flags that mark the control locations to be out in the field for at least a month, maybe several months, and even if we have to remove the markers, the MapRun app will still allow you to know when you've gotten to a control.
If you actually go out and run one of the courses, please let me know.

, Course Setter

Course Maps

Links to all the course maps are below. The scale is 1:5,000 (shown on the maps), and the contour interval is 5 meters (not shown on the maps). All the maps fit on 8½"x11" paper. (In case you can’t print the maps at the intended scale, note that the north lines are 250 m apart, which is not noted on the maps.)

The control descriptions are included on the maps. As you can see, there are many controls on each course. 🙂

There are two maps for each course, because there is a map exchange part way through each course. Please be sure to read the description here of how you are intended to deal with the two maps while on the course.

Brown Course

Details: 3.7 km, 85 m climb (2.4%), 30 controls

Brown Course, Part 1 (700KB PDF)
Brown Course, Part 2 (720KB PDF)

Green Course

Details: 5.1 km, 165 m climb (3.3%), 36 controls

Green Course, Part 1 (705KB PDF)
Green Course, Part 2 (720KB PDF)

Red Course

Details: 7.0 km, 280 m climb (4.0%), 44 controls

Red Course, Part 1 (870KB PDF)
Red Course, Part 2 (875KB PDF)

Use of the MapRun App  

Note: These instructions are available in this PDF file (76KB) if you want to print a copy.

Basic Instructions

1. Install the app and load the event

2. Run the course

3. Results

Additional Notes

  1. If you accidentally trigger the course timer before you are ready, hit the home icon in the upper left corner and then confirm that you want to exit. Tap “Go to Start” again when you are ready.
  2. If your result fails to upload to the main database at the Finish, you can upload your result manually when you get within Internet signal range. From the main menu, tap on “Show Results” to see a list of all your recorded results using the app. Open (by tapping on) the result in question, then from the menu on the top-right, select “Upload (Manual)”. You should see confirmation that the upload was successful.
  3. If one of the checkpoints fails to register that you passed through it, it’s probably because the GPS had an error greater than 15 meters. You can submit a revised result using a radius value greater than 15 meters. From the menu on the top-right of the Results list screen, select “Review Results (HITMO)” and tap on the info button in the top-right to get on-screen instructions on submitting a revised result. Use 30 meters as the Tolerance (size of new punching radius in meters).
  4. If the app does not beep when you are at the Start, you may need to restart your app or even restart the phone.
  5. MapRunF will not punch the Finish until you have visited at least one checkpoint. Be careful not to get close to the Finish in the middle of your run. Once the Finish is triggered, the race is done.
  6. You may find it helpful to store your phone in a carrier so that you can run without having to carry it in your hand. I have personally found a fanny pack running belt very helpful. Although, if you are using the MapRunG app on your Garmin watch, it wouldn’t be necessary to take the phone with you.
  7. Running the GPS continuously takes a lot of battery power. Make sure your phone is fully charged before you start.
  8. Please direct all concerns or feedback to .

Frequently Asked Questions

  1. Why is 15 meters used as the GPS radius?
    Most recreation-grade GPS devices have an inherent error of about 3–10 meters. That error can be larger when moving. If a radius less than 15 m is used, a number of checkpoints would not be registered. If a larger radius is used, you would often get a “punch” recorded before you even see the feature or the flagging. Also, the time measurement error between the Start and Finish becomes greater. See the next question for details.
  2. Are the course times accurate to within 1 second?
    No, because of the inherent error in GPS measurements, you may trigger the Start and Finish between 15 meters (or more) before or after the actual locations. So there could be a 15-meter discrepancy in where both the Start and the Finish are triggered for a total of 30 meters. 30 meters at 8 min/mile pace corresponds to 9 seconds of time. In reality though, the errors are not usually this large, and the elapsed times are usually accurate to within 4-5 seconds of the true time, but definitely not 1 second. There is also a range of locations that the beep will occur at for every control, so that will add to the time discrepancy between competitors. As such, it’s not really comparable to E-punch timing.
  3. I noticed that there is an Options and Settings button on the main menu. Is there anything useful there?
    No, most of these settings are locked, and the ones that aren’t are best left in their default setting.

Additional Comments

The following information was posted to the BayONet ( on Dec. 6, 2020 (,,,20,0,0,0::recentpostdate%2Fsticky,,,20,2,0,78773304).

The Bon Tempe courses are now set up on MapRun so you can run the courses on your own time. Small landscape flags with control numbers will be left out in the terrain. Keep in mind that you should only visit the park if it is consistent with COVID-19 lockdown situation of the county you live in.

MapRun is an app that uses the GPS capability of smartphones and GPS watches for punching and timing, avoiding the need to put markers and SI units out on an orienteering course. MapRun is available on iOS and Android phones, and Garmin watches. You can read more about MapRun at their website (, but the information there is a bit convoluted since there is information for different versions of the app, so I tried to create a simple instruction sheet for MapRun here ( [Ed note: As of Dec. 6, 2020, that online document has the same information as above on this page and in this PDF file (76KB).]

One of the features of MapRun is that it automatically uploads your GPS track to RouteGadget at the end of a run, and doesn’t require any adjustments since the map is georeferenced. (Note: The RouteGadget event generated in MapRun is separate from the RouteGadget event generated from SPORTident splits.) As an example, the MapRun results file for my Friday run of the Red course is here ( You can view the RouteGadget event by clicking on “Track”. (Alternatively, you can go directly to the RouteGadget event here (

Some more background:

I’ve been working extensively with MapRun for the virtual NAV-X event ( on the new Annadel map. I tested UsynligO ( and Sporteering (, and found MapRun had the most advanced features for putting on a virtual event. MapRun was created in Australia, and is also popular in Canada and the UK. I am one of two administrators in the U.S., and have been given permissions for the USA/California event “folder”. If you are interested, you can find the Annadel event in the USA/California/NAVX folder. I’m happy to help set up future events for BAOC in the USA/California/BAOC folder.

I’ve really found MapRun to be very fun and liberating, because you don’t need to think about punching. I keep my phone in a fanny belt and just run until I hear the beep!

Bill Cusworth