Middle Info

Bowie Map – Competitor Summary

The Bowie map (a.k.a., Fran Uhler Natural Area) contains large flat regions within the Patuxent River flood plain, as well as some sudden transitions to steep hillsides. The contour interval is 3 meters. The trail network is both maintained and unmaintained. Most of the maintained trails are unpaved.

The Bowie map was originally created for local club usage by Dave Linthicum, mapper of the 1981 US Team Trials and 1988 US Championships venues, among other maps. He is highly experienced and was thorough in his accurate representation of this terrain.

Key Takeaways

The Bowie map has been carefully prepared to balance accuracy, fairness, and legibility in a uniquely detailed area. Although created at 1:7,500, the symbol sizes closely match ISOM 2017-2, Rev. 6 symbols at 1:10,000, to ensure a clear and consistent navigation experience.

Printing is at 1:5,000 except for M21+ and F21+. Water features follow a clear, logical system. Real‑world conditions vary along with orienteer perceptions–water with dark blue bank lines is uncrossable anytime. Vegetation is partly simplified with less usage of light green. Since there are several differences from a fully ISOM 2017-2, Rev. 6 map, QOC highly recommends competitor participation in the Model Event which is being offered. For more detailed descriptions, read further.

Model Maps

The Bowie/Middle model map is available at both course map scales. Click here for the 1:5000 model map, and click here for the 1:7500 model map.

Vegetation

One may pass through wide-open vegetation and then suddenly encounter dense and thorny fight. These transitions may be densely spaced. Three green forest vegetation symbols were used. However, in the area of competition little light green (Slow Run) is present. The low vegetation symbols were used sparingly. Some vetter’s perceptions of running speed indicate often slower than expected paces in White Forest, yet faster speeds in Medium Green and Fight:

• White woods vary from very open 100% to 70% running speed

• The medium green color ranges from 30 to70% running speed

• Fight is from 0% to 30% running speed instead of 0% to 20% running speed

There are thorns, sometime single strands, sometimes more. Lower leg protection is recommended. Rootstocks are not mapped.

How the Scaling Works

You will find there is an unusually high density of small landforms that were created by mining activity 90 years ago. To keep the map readable at running speed, multiple symbols have been consistently resized so that, although the map was created at 1:7,500, the symbols match the ISOM 2017-2, Rev. 6 dimensions used for 1:10,000. This preserves clarity while still showing the terrain’s richness. This approach follows ISOM’s core principle that legibility must never be compromised. In terrain with this level of detail, using full‑size 1:7,500 symbols would create clutter and overlapping features. The adjusted symbol sizes ensure that the map remains fair, accurate, and easy to interpret. Please note that actual printing of the Bowie map for the competition may be at 1:5,000, dependent on course.

There are a few other non-standard symbols on the map as explained below.

Reference Table of Other Non-Standard or Adjusted Symbols

These adjustments (see table below) preserve clarity in dense terrain. Symbol meanings remain unchanged.

Middle Course Notes: (Course Setter: Mihai Sirbu)

A high-speed rail track crosses the map. There is no reason to get close to or cross the tracks. They are out-of-bounds. Stay away!  

Most of the woods are open and very runnable. Respect the dark green. Even if vegetation is just starting to grow in the spring, thorn thickets can be quite vicious. 

The map has extensive water features. Depending on the amount of rain in the lead-up to the event, some water features may be full, partially full, or even dry. For example, mapped dry pits may contain significant amounts of water. Continuous dark blue water (rivers, ponds) is not safe to cross. Some beginner/intermediate trails have segment mapped as wet ditches. The amount of water/mud there depends on recent rain.

In the advanced section, there are a number of paired pits and knolls; in other words, a pit was dug, and the resulting earth was heaped on the side, forming a knoll.  Sometimes, either the pit or the associated knoll did not meet the mapping threshold, so they do not show up on the map. At other times, the smaller heaps of earth are mapped as “broken ground” adjacent to the pit.

Advanced courses have a remote start. A shuttle will take competitors to the NW Amtrak parking lot. From there, signs follow the signs on Lemons Bridge Road for 500m to the advanced finish/start areas. Remember to stay away from the train tracks. 

Near the end and at the start of some courses, there is a very technical area with many controls. Please check the control number before punching.

Green, red and blue:  The courses pass by or intersect a "green" marsh.  Water and mud might be deep and/or unpassable.  Use it as a route choice at your own risk.

Blue: You will get wet. Leg 4-5 goes across a yellow/open marsh.  The water is about knee high, can be very cold, and the bottom is firm. Passage is straightforward even if uncomfortable.

The beginner/intermediate start is close to the Assembly area in parking lot "I".  Do not walk or run on the road on the way to the start.

White course: Do not run on the road.  The course has a loop; in other words, the leg 2-3 is the same as the leg 9-10, so controls 2/9 and 3/10 will be visited and punched twice. Leg 7-8 is streamered with orange, to guide to a safe crossing of the creek.

Yellow: Do not run on the road.