Lake Accotink

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September 15

Welcome to National Orienteering Day, where you just might win a prize randomly as well as have fun orienteering!

MTBO Pre-Registration now open. Optional pre-registration for MTBO participants is now available until Friday via our friendly Pop-Up Registration Form.

Everyone is welcome at the two events taking place here on Saturday, Sept. 15. In the morning, weather permitting (and the forecast for the rest of the week looks good), bring your bikes and choose between an easier (intermediate) and a harder (advanced) mountain bike orienteering ("MTBO") course. In the afternoon, walk or run your choice of a beginner (white or yellow), intermediate (orange), or advanced (brown, green, red or blue) course. For advanced orienteers choosing green, red or blue, the courses are designed as a two-loop "farsta" with a mass start at 12:30pm, but you can also start on your own anytime during the start window like usual if you're not farsta-inclined. Course details are posted below.

New to orienteering? We will hold beginner clinics continuously as needed during both events; just tell the friendly folks at registration if you'd like to be in one and they'll take care of you. Also, make sure to check out our Your First Event and For Beginners webpages, and if they don't answer any question you have, just use our Contact Us form and ask away!

Group Leaders: please see our For Group Leaders webpage and then contact us so we can get you registered in advance.

Though totally unconnected to the (out)door prizes being given away as part of National Orienteering Day, we'll also compute the results for an orienteering duathlon in intermediate and advanced categories. There will be two classes with rankings based on the sum of one's time per kilometer on MTBO and traditional orienteering courses - one combining the results of the intermediate MTBO and orange courses, the other combining the results of the advanced MTBO and any one of the green, red or blue courses with the lowest sum of TPKs winning in each category.

Webcam image courtesy of FCPA


Lake Accotink Park, Lower Parking Lot, Springfield, VA (National Orienteering Day)

RegistrationOptional pre-registration is now offered for MTBO participants - get a discount and guarantee yourself a map by just clicking on our Pop-Up Registration Form. MTBO preregistration will close Friday afternoon. Day-of (walk-up) registration applies to all foot-O participants as well as those MTBO participants choosing not to pre-register.
Start TimesYou may start your course at any time during the start window listed below for your event with the exception of the farsta courses, for which there will be a mass start at 12:30pm.
ScheduleSaturday, September 15
8:00 amNational Orienteering Day: MTBO registration opens
8:45 amNational Orienteering Day: MTBO pre-race briefing
9:00 amNational Orienteering Day: MTBO start window opens
10:00 amNational Orienteering Day: MTBO registration closes
10:30 amNational Orienteering Day: MTBO start window closes
11:30 amNational Orienteering Day: Classic orienteering registration opens
12:00 pmNational Orienteering Day: Classic orienteering start window opens
12:00 pmNational Orienteering Day: MTBO courses close
12:30 pmNational Orienteering Day: Mass start for farsta courses
1:45 pmNational Orienteering Day: Classic orienteering registration closes
2:00 pmNational Orienteering Day: Classic orienteering start window closes
4:00 pmNational Orienteering Day: Classic orienteering courses close
Event Director:Kyle Bondo
Course Designer:Jon Torrance
Location Details

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Lake Accotink Park
Lower Parking Lot
Springfield, VA
Google Map

From southbound, I-95 Springfield West, first right on BacklickRoad. Left on Highland to Park.Park in the lower parking lot below the dam.

From northbound I-95 Springfield West to third stoplight. Right on Hanover, left on Highland (sixth stop sign) to Park.Park in the lower parking lot below the dam.

From southbound, I-495 Braddock Road East. Right at second stop light,onto Heming. Follow Heming. Pass under the beltway and continue pass two streets on the right.The park is on the right where the street begins to turn to the left. This is the upper parking lot. Walk downhill next to the fence to the dam.(This avoids the Springfield Interchange with I-95 which may have a back-up).

From I-395, Edsall Road West to end. Left on Braddock Road to third stoplight. Right onto Highland to Park. Park in the lower parking lot below the dam. (This avoids the Springfield I-95 Interchange which may have a back-up).

Course DetailsNational Orienteering Day
Course NameLength (km)Climb (m)No. Controls
Intermediate Mountain Bike 5.626015
White 2.912010
Yellow 3.614011
Orange 4.722513
Brown 4.620517
Green 623520
Advanced Mountain Bike 7.731516
Red 725523
Blue 8.836527
Course NotesNational Orienteering Day

MTBO course notes: If you're wondering what MTBO is about, you might want to follow some of the links under the heading Background on Mountain Bike Orienteering on the web page for our last MTBO event. As at that event, participants will be required to stay on the trails (no short cuts through the woods) and the trails will be open to other users so the usual rules of yielding to pedestrians and keeping an eye out for all other trail users apply.

The MTBO courses use that portion of the park southwest of the lake containing one major trail running from the dam at the south end of Lake Accotink, where the start/finish will be located, to the northwest end of the park and a complex network of easy to moderate difficulty single track. There are a few descents on which less experienced mountain bikers will probably want to be cautious but in general it's possible to ride fast just about everywhere. The challenge will be to quickly decide what the fastest route between controls is and ride it fast without getting lost. Both MTBO courses will use maps printed at a scale of 1:7,500 with a 5 meter contour interval and the trails converted to international MTBO symbols.

Helmets will be required equipment for MTBO participants. Also, participants are encouraged to bring the map carrying system of their preference although there will be safety pins and polyethylene map cases available to support the low-tech option of safety pinning your map to your torso. Note that the map will be 8.5"x11" and that you will be given the map at the start, a minute before starting, so you might want to practice inserting a piece of paper that size into whatever system you will use to be sure you can do it that fast.

Note: if the MTBO courses seem short compared to the traditional orienteering courses, keep in mind that course distances are assessed as the crow flies between controls. Since running off trail is permitted in traditional orienteering but won't be permitted in the MTBO, the multiplier for the stated distances to get the actual distances participants will cover will be significantly higher for the MTBO courses. It's hard to be certain absent international elite MTBO athletes to test ride the courses but probably the advanced MTBO course would qualify as a middle distance MTBO race by international standards, with expected winning time somewhere in the neighbourhood of 50-60 minutes.

Classic orienteering course notes: the map has, within the last month, been updated to reflect changes to the trail network over the course of the last few years and also with the addition of a number of new rootstocks, some of which are used as control features. It might nevertheless be a good idea to keep in mind that whether all rootstocks in the terrain are on the map and vice versa is always a known unknown.

The map shows most of the forest as open, runnable white woods. However, at this time of year almost all of the forest would be more accurately mapped as light green, just slightly less open that would merit showing as white on the map - runnable but not quite at top speed and with visibility quite noticeably less that in our most open Mid-Atlantic woods. Some of the light green areas that were on the map have been removed since they're no longer visibly distinct from the surrounding woods mapped as white. Some remain since they still are noticeably thicker and slower. A few areas of darker green have been added to the map and are, along with older mapped darker green areas, thick enough to be worth some effort to avoid. It should be noted that the first controls on the orange and all of the advanced courses are in a block of woods mapped as mixed white and light green woods that it would probably be more accurate to map as a mixture of medium green, light green and maybe a smidgen of white. Regrettably, there wasn't time to update the vegetation mapping there so please be cautious and know that things will get better after that.

All maps will be printed at 1:7,500. The contour interval is 5 meters. The green, red and blue courses involve two loops, each one printed on a separate map. The two maps will be packaged in one map case, with the printed side of the first loop map showing. Both loops start and end just south of the dam. If you aren't taking part in the mass start, you'll obtain your maps, punch the start box when you start, punch a control at the end of the first loop and discard the first loop map, then punch the finish when you finish the second loop. If you are taking part in the mass start, we'll distribute the maps shortly before the start, face down, as we do at the Chase. Please resist the temptation to look at the map before the mass start. There will be no start punch for people doing the mass start. The race procedure will be otherwise as described above.

Entry FeesMountain Bike Orienteering

Online pre-registration: Adults - $6 members/$10 non-members Juniors (under 21) $4 members/$6 non-members

On-site registration: Adults $10 members/$15 non-members Juniors (under 21) $8 members/$10 non-members

Groups wanting more than one map will be charged $4 in addition to the base rate per additional map used.

Entry fees will be refunded in the event of cancellation due to inclement weather.

Classic Orienteering

Individual Entries

Non-Member: $10/adult, $6/junior (under 21 years old)

Member: $6/adult, $4/junior (under 21 years old)

Team or Group Entries

Participants are welcome to compete together as a single team entry. Teams containing one or more nonmembers are charged the nonmember individual rate. Teams containing one or more adults are charged the adult individual rate. For teams to receive member or junior rates, all members of the team must be members or juniors, respectively. Each extra team map beyond the first is an additional $4. Individuals or teams desiring to compete on a second course can do so for a reduced fee of $4/map.

Important Notes
  • At the event, we can only accept payment in cash or check; online, you may use a credit card or PayPal account.
  • Most of our events use electronic timing. We will provide you with an electronic timing chip (aka e-stick, finger dibber, or SI-card) for free if you don't own one. Loaned e-sticks that are lost incur a $40 replacement fee.
  • Compasses are available at no charge, but if lost incur a $15 replacement fee.
  • Please provide collateral (driver's license or car keys) when borrowing a compass or e-punch.
  • For additional safety, whistles are available for sale at $1/each.
  • Free beginner instruction is always available - just ask at the registration table.