• 38.888752, -121.018637 (map)
  • Olmstead Loop Trailhead
  • Cool, CA, 95614
  • United States

2023 Nav-X Challenge @ AUBURN

Quick Info

  • Date: Saturday 1 April to Wednesday 31 May

  • Location: Auburn, CA

  • Courses: 2h & 4h GPS Map Trek

  • Registered entrants: Follow this link!

Introduction

  • The 2nd event in the 2023 NAV-X Challenge brings us to a classic endurance sports venue in the foothills near the town of Cool, CA.  

  • 51 checkpoints are marked on a new map based on Lidar data of the Olmstead Loop area in Cool - the old version of the map was used in 2019 (mountain bike) and 2021.

  • You have 2 or 4 hours to try and get to as many checkpoints as you can.

  • The area is still wet from the recent rains and the poison oak will soon be in bloom so we recommend full leg covering.

  • Due to the poison oak, the course may be better run in April rather than May.

  • All the instructions including directions to the Start are below.  Be safe and have fun!

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, and poison oak.

  • WATER - There are no open water spigots at the start/finish. The creeks are mostly dry but there is a small lake in the middle of the map. I recommend bringing all the water you need with you.

  • Mountain Biking is very popular in Annadel so watch out for bikes moving at high speed. The riders are mostly very considerate.

EVENT INFORMATION

  • MAPRUN6 - Please see this page for instructions on how to use the MapRun6 smartphone app.  It’s important that you load the course while you still have Internet service.  Search for “2023 Nav-X GPS Map Trek Auburn” and pick the right course - 2hr or 4hr.

  • DIRECTIONS TO PARKING - The parking area is located at the Olmstead Loop Trailhead.

    • From Sacramento and Bay Area, take I-80 East to Auburn.  Take exit 119C/Elm to CA-49 S, continue East/South 6.1 miles to the town of Cool.  Right turn onto Florian, then take an immediate left into the parking lot.

    • From Truckee/Reno, take I-80 West to Auburn. Take exit 119C/Elm to CA-49 S, continue East/South 6.1 miles to the town of Cool.  Right turn onto Florian, then take an immediate left into the parking lot.

    • From South Lake Tahoe, take US-50 West to Placerville. Take exit 46/Coloma Right to CA-49 N, continue North 19 miles to the town of Cool.  Left turn onto Florian, then take an immediate left into the parking lot.r. The start is 0.4 mi from Summerfield, on the left (north) side of the street.

  • PARKING - There are two parking areas.  The large one farther from Hwy 49 is for horse trailers.  Please use the first parking area that is intended for hikers, runners and mountain bikers.  Parking is $10 if you don’t have an annual pass.

  • BATHROOMS - There are two porta potties at the hiker parking, and 2 bathrooms at the equestrian parking.

  • GEAR RECOMMENDATION - We recommend participants bring the following:

    • Smartphone - goes without saying since we are using an app for timing

    • Compass

    • Long pants or at least gaiters for the tall grass and brushy vegetation

    • Snacks & Water, especially if you are on the 4-hr course

  • TRASH - There is no garbage removal service at this venue, so you must carry out what you bring in.  Practice LNT (Leave No Trace).

MAP & COURSE NOTES

  • TERRAIN - The area is located on a plateau East of the North Fork of the American River.  Rolling, oak studded hills, with interspersed open land, as well as some pine groves make for relatively fast terrain, though there are places that are more overgrown and brushy.  Many trails intersect the area, including many animal trails that may not be on the map.  There are several ruins and other artifacts of earlier human settlement.  Fences criss-cross the area and most of them can be crossed with not too much trouble by looking for openings, etc.  A note on the creeks in the area:  Crossing creeks where no trail crosses can be “risky”, because there could be a lot of blackberries and poison oak, making travel very slow. Trail/creek crossings are mostly fine and some have rocks to step on or bridges. But a handful of crossings can get mid-calf to knee deep. Due to the wet winter, the lowlands are saturated with water. Don’t expect dry shoes on this one!

  • COURSE - The course was designed by Heidi Cusworth and the field work was done by Roy Malone. There are 51 checkpoints varying in point value from 10 to 100 points. The approximate straight-line distance to get all controls is ~24.5 km.  

  • 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. The late penalty is 10 pts/minute (this is now fixed on the app). The maximum points possible is 2570. 

  • MARKERS - Each checkpoint is marked with orange biodegradable flagging. There is no writing on the flagging. The MapRun6 app will beep automatically when you get close to the checkpoint based on your GPS reading. NOTE: Flagging close to trails may not be there when you run the course.  People sometimes remove flagging in an effort to “bring nature back”. Also, sometimes animals will remove the flagging.

  • MAP PRINTING - To keep costs down, we are not printing and mailing maps. We are providing two PDF versions of the map for you to print before doing the course. The first PDF is a 1:20000 version of the course that will print on 8.5 x 11 that you can use for route planning. Since you won’t be able to read much of the detail at that scale, we have also provided a second pdf at 1:10000 that will print onto multiple sheets of 8.5 x 11 paper with overlap between sheets. The MapRun6 app also contains a low resolution version of the orienteering map with the checkpoints shown, but no control descriptions.

  • MAP - This is a brand new map suitable for map adventures on foot and mountain bike.  It is considered an "improved Topo" map. The contours and vegetation were both created with new LiDAR data. Many animal trails are quite noticeable, but most are not on the map.  If a trail is on the map, it is well traveled. The dark green on the map truly is very nasty (manzanita or poison oak) and should be avoided as much as possible. The narrow ride symbol is used for old road grades and can be very overgrown.