2024 Nav-X Challenge @ Black Diamond Mines
Quick Info
Date: Friday 1 March to Tuesday 30 April; suggested race time is Sunday, 21 April at 10am. Pre-printed maps will be available.
Location: Black Diamond Mines Regional Preserve, Antioch, CA
Courses: 2h & 4h GPS Map Trek
Price: $12 (2h) & $17 (4h)
INTRODUCTION
The first event of the 2024 Nav-X season will take place at Black Diamond Mines Regional Preserve, a park with a history of coal and sand mining as well as ranching.
Upon registration, you will receive (1) registration confirmation, (2) within 24 hours, a separate email with links to map documents.
The park is open from 8 am to dusk. Our suggested race time is Sunday, 21 April at 10am. We will have a Nav-X team member there to hand out pre-printed maps (no extra charge) if you register by April 19. Since this is not an official event, there will be no signage so just meet the Nav-X staff member at the start triangle on the MapRun course 30 min before the mass start time of 10am.
39 checkpoints are marked on the map - you have 2 or 4 hours to try and get to as many checkpoints as you can.
We will be using a Smartphone app named “MapRun” to record your visit to each checkpoint. The app will record a “punch” automatically using your GPS position.
Be safe and have fun!
EVENT INFORMATION
MAPRUN - Please see this page for instructions on how to use the MapRun smartphone app. It’s important that you load the course while you still have Internet service. Search for “2024 Nav-X GPS Map Trek Black Diamond Mines” and pick the right course (2hr or 4hr).
DIRECTIONS TO PARKING:
Take Somersville Road south from highway 4 until it ends at the park gate. The park is open from 8am to dusk.
Proceed 1 mile to a kiosk. Entry fee for parking is $5 when the kiosk is attended, otherwise parking is free. The 3 times I visited the park to set the course (a Thursday, Saturday, and a Sunday) there was no fee.
Continue about 1 mile to the upper parking lot. There are restrooms located here and the start and finish is about 100 meters along a trail to the southwest.
BATHROOMS - There are restrooms at the parking lot, also a few scattered on the course.
GEAR REQUIREMENT - you must carry the following on your course
Smartphone/GPS watch - goes without saying since we are using an app for timing.
Compass
Whistle for safety
GEAR RECOMMENDATION - We also recommend participants bring the following:
Cleated shoes - you may be traversing steep slopes
Long pants and gaiters for the grasses and thistles
Snacks & Water
TRASH - While on the course, practice Leave No Trace (LNT) - bring all trash back to the parking area.
MAP & COURSE NOTES
TERRAIN - Open grassland, chaparral and some oak wooded areas. Some areas are quite steep including cliffs. Historic mining structures dot the park, all known mine entrances have been sealed.
PROHIBITED AREAS: Residences, maintenance yard, dense brush areas. Observe the restricted areas (hashed on map) and any park signage. The dark green areas in the southern part of the map are marked by the park as restricted, but are not a desirable route choice in any case.
MAP - The map has 5 meter contours with vegetation, roads, trails, fences, cliffs, and other features added using aerial photography. A small section of the map in the SW area contains orienteering-level detail. The vegetation and cliff mapping is somewhat generalized. Unfortunately, Lidar data is currently only available for the western ⅓ of the park and was not used to generate the contours. However, the contours are pretty good despite not being Lidar quality. As the park is used for cattle grazing, there are many cow paths in the terrain. The major cow paths have been mapped but there are many more smaller ones that are not on the map. These paths are especially helpful to follow along steep hillsides allowing you to get a foothold on the steep slopes.
COURSE - There are 39 checkpoints varying in point value from 30 to 100 points. Generally, higher value controls are either inconveniently located, harder to find, or a greater distance from the start/finish. The total possible points are 2950. The total straight-line distance to get all checkpoints is about 26 km (compared with about 24 km for the 4-hr 2021 course).
SCORING: Just like our other events, each checkpoint has a point value reflecting the difficulty (higher point value for tougher checkpoints). The point value is the “10 part” of the checkpoint code. Examples: 33 = 30 points, 50 = 50 points, 88 = 80 points, 102 = 100 points, etc. Late penalty is 10 points per minute.
MARKERS - Most checkpoints are marked with biodegradable ORANGE. Be aware though, that as time goes by, animals and hikers may remove some markers so they are not guaranteed to be there when you get there. Your phone/watch beeping/vibrating is what matters, and what keeps score.
START - The start area is shown on your map as a triangle. It is located where the trail south of the parking lot. Do not approach the start until you are ready to go! Your GPS device will start you automatically and alert you by beeping once you are within 15 meters of the spot.
FINISH - the finish is marked on your map with a double circle and is located at the same spot as the start. When you are within a couple meters of the spot, your GPS device will register a finish. Do not approach the finish until you are ready to end your course. (Depending on the device, it may be possible to continue the course after this, for example if you approached the finish spot by accident. However, this might not work for you, so we recommend you don’t go near the finish until you are done.) Remember to upload your result after you finish (if it doesn’t happen automatically).
MAP PRINTING - You will need to print your own maps. We are providing a Zip file with 2 separate PDF files of the map for you to print, cut and tape before doing the course. It is on two 8.5x11 sheets at 1:15,000 scale. The control descriptions are on the map, and we are also providing a separate PDF with the descriptions only.
Thanks for reading, and have fun! - Kyle Poland, Bill Cusworth and the Nav-X team