2026 Nav-X GPS MAP TREK #6 @ 100 Lakes
Quick Info
Date: Wednesday 1 July to Wednesday 30 September
Location: Grouse Ridge Campground OR Carr-Feeley Lake Campground
Courses: 4h & 8h GPS Map Trek
Price: $22 (4-hr) & $32 (8-hr)
LINKS to MAPRUN COURSES (click link while using smartphone after July 1)
4-hr course
8-hr course
INTRODUCTION
The 5th event in the 2026 NAV-X Challenge brings us to the mountains near Yuba Gap N of Hwy 80 in the Tahoe National Forest. Our last event at 100 Lakes was back in 2021.
We have set up a course with 60 checkpoints. Get as many checkpoints as you can in either 4 or 8 hours using the Smartphone app named “MapRun” to record your visit to each checkpoint based on your GPS position.
For the first time, we are setting up the course as “Start Anywhere” with 2 parking areas to choose from. More info. below.
The competitive window for this event is July 1 - September 30, 2026. Results during this time period will be included in the official results and accrue Nav-X series points but the course will still be available on MapRun until Dec 1, 2026, after which it will move to the archived courses. Upon registration, you will receive (1) registration confirmation, (2) within 24 hours, a separate email with links to map documents.
Pre-printed maps are available by mail for $10. Maps will generally be mailed to arrive in your mailbox within 7 days of registering. For 100 Lakes, the deadline for ordering pre-printed maps is September 1.
Note that we are not having an in-person map handout for this event. A great time to do the course would be combined with attending the Tahoe 4-days event put on by BAOC on July 31-August 3.
IMPORTANT SAFETY NOTES
YOU ARE DOING THIS AT YOUR OWN RISK - WE TAKE NO RESPONSIBILITY FOR ANY INJURIES OR DEATH. HAZARDS INCLUDE STEEP HILLS AND CLIFFS, LOOSE ROCKS, OCCASIONAL DENSE AND SHARP BRUSH, POISON OAK, MOUNTAIN LIONS, BEARS AND RATTLESNAKES.
WATER - There is no water at the parking area - bring your own. There are a few creeks flowing at low rates, and a few lakes with “clear” water. But this is a dry year, and if you do this in August or September, it will be very dry and some of the lakes will be dry or pretty mucky. Recommend bringing all the water you will need on course from the start.
CELL COVERAGE - Unfortunately, there is very little cell phone coverage in most locations on the map.
WHISTLE - Due to the self-serve format, you may be completely on your own when you run your course. Be aware of this! You should bring a whistle in case of an emergency. .
TICKS - are present - check body and clothing after your run.
REGISTRATION
An Orienteering USA membership is not required: instead, use the Enter Data Manually option instead.
If you are part of a team, everyone on your team (over 12 years of age) must register separately.
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 “2026 Nav -X GPS Map Trek 100 Lakes” and pick the right course (4 hr or 8 hr). Or you can click one of the links provided above to load the course.
START ANYWHERE - For the first time ever, we are setting up this event as a “Start Anywhere” course. This means that there is no start and finish marked on the official map; in MapRun there is a start and finish marked off of the course area and you should ignore them. The first checkpoint that you visit becomes the start and finish for your course and that checkpoint will lose its point value. Therefore, part of the strategy will be deciding which checkpoint to take first (hint: pick a low pointer to start with). We decided to set up the course this way because this year there are 2 access points with parking for the area: the Grouse Ridge Campground start that gets you close to the center of the map but has a very rough dirt road access, and the Carr-Feeley Lake Campground start which is on the west side of the map but the dirt road access is easier for most cars. The total driving distance is about the same for both campgrounds but the Grouse Ridge Campground takes longer to get to.
DIRECTIONS to Grouse Ridge Campground:
From Truckee: https://goo.gl/maps/FLQ7GZH9c1KvyXng7
From Sacramento: https://goo.gl/maps/fCCEzfnSbmPATaKy8
ROAD: The turnoff of Bowman Lake road for the Grouse Ridge Campground comes first. This is the start of a 6 mile dirt road which takes 30-45 minutes to drive. The road is rutted in a few locations and a higher clearance vehicle is recommended: trucks and SUVs can make the drive and I saw some smaller SUVs (e.g. Nissan Rogue) also make it. This road is not recommended for sedans.
PARKING: When you get to Grouse Ridge, follow the left road to the trailhead parking at the far end. From here, it is about 200 meters to the nearest checkpoint. Proceed on the main trail north from the parking area and the 100 lakes trail signage.
CAMPING: Grouse Ridge Campground has 6 first come first served campgrounds with parking directly at each campsite; no charge to camp. There is also a parking area near the campground bathroom where you can discretely sleep in your car if you are set up that way.
DIRECTIONS to Carr-Feeley Lake Campground
From Truckee: https://maps.app.goo.gl/NNMaBXYnPBf8AfWt5
From Sacramento: https://maps.app.goo.gl/XkDWh7bjjsK9kJCP9
ROAD: The turnoff of Bowman Lake road comes second. This is where the dirt road begins which takes 15-20 minutes and is passable by more vehicles.
PARKING - When you get to the campground, park in the gravel parking lot. From here it is about 2 km to the nearest checkpoint. Proceed on the main trail east from the parking area.
CAMPING: Carr-Feeley Lake Campground has about 6 first come first served campsites around the lake that you need to walk in to; no charge to camp. You can also discretely sleep in your car at the trailhead campground if you are set up that way.
BATHROOMS -The Grouse Ridge Campground has a building with pit toilets. The Carr-Feeley Lake Campground has a set of port-a-pots at the trailhead.
GEAR RECOMMENDATION - We recommend participants bring the following:
Smartphone - goes without saying since we are using an app for timing, and/or Garmin watch.
COMPASS, and know how to shoot a bearing. It’s critical on this course.
Headlamp as a safety precaution
Wind/rain jacket - it’s the Sierra where afternoon thunder showers can happen on a moment’s notice
Long pants or at least gaiters
A small roll of duct tape - can be used for blisters and to stabilize a rolled ankle.
Mosquito repellent. They are quite aggressive in the coniferous areas near water.
TRASH - Bring it with you, there is no trash cans/service. While on the course, practice Leave No Trace (LNT) - bring all trash back home.
BE DISCREET - We don’t have a permit so try not to be too noticeable when entering or exiting off-trail areas.
MAP & COURSE NOTES
TERRAIN - It's wonderful terrain with lakes everywhere, and streams connecting them. But it’s physical, with lots of granite ledges scattered throughout. Fields of low brush in some areas make it look like there is no way through but on closer look you’ll find ways to get forward without too much bush-whacking. In fact, a big part of the fun on this course will be route finding. You won’t be setting any pace records here, but it’s so beautiful, you won’t mind.
MAP - The map was created in 2018 from high quality Lidar data with no field checking. The map scale is 1:15,000 and the contour interval is 5 meters. Vegetation density (3 shades of green), cliffs, water features, roads, trails, and other features were added using Google aerial imagery along with the Lidar data. The contours are very accurate, vegetation is pretty accurate, but there are streams/creeks that are not on the map, and many of them are seasonal anyway. There are sometimes trails near the more popular lakes that are not marked on the map.
COURSE - The course was designed by Kyle Poland. There are 60 checkpoints varying in point value from 20 to 100. The maximum possible points is 3350. The total straight-line distance needed to get all the checkpoints is about 19 km. Generally, higher value checkpoints are farther from the start, harder to find, or some combination of both. In true rogaining style, some checkpoints are located on features that are not on the map.
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, etc. Late penalty is 10 points per minute or any part of a minute (1:01 late = -20 pts).
START AND FINISH - As mentioned in the previous section, there is no start and finish on the map. The first checkpoint that you visit becomes the start and finish for your course and that checkpoint loses its point value (so pick a low pointer for your first checkpoint). The MapRun app will start you automatically and alert you by beeping once you are within ~15 meters of the first checkpoint that you visit. MapRun, however, requires a start to set up any course. This start gets assigned the highest point value when the course is started at a regular checkpoint. Since we don't want this extra high value checkpoint on the course, we placed the start off the map to the east. When you press “Go to Start” in MapRun, it will center the screen on this spot and you will have to scroll over to where you parked if you want to see your GPS location - the red dot on the map which disappears as soon as you visit your first checkpoint. Remember to upload your result after you finish (if it doesn’t happen automatically).
MARKERS - Checkpoints are marked with biodegradable orange or pink flagging except those on trails and #101. Be aware though that as time goes by, animals and hikers may remove some of the flagging, so it is not guaranteed to be present.
MAP PRINTING - We are providing a Zip file with the map documents in PDF format within 24 hrs of registration. The text checkpoint descriptions are on the map. You will need to print your own map or purchase a pre-printed map (1:15,000, 11”x17”). For $10, you can have a map mailed to your address (allow 7 days for maps to arrive); this option is available until September 1 on the registration page.
If you want to report any problems with the course, please email info@navxchallenge.com