2023 Nav-X Challenge @ ANNADEL

Quick Info

• Date: Monday 1 March to Friday 30 April

• Location: Annadel State Park, near Santa Rosa, CA

• Courses: 3h & 6h GPS Map Trek

• Registered entrants: Follow this link!

Introduction

• The 1st event in the 2023 NAV-X Challenge brings us to beautiful Trione-Annadel State Park, located in eastern Santa Rosa.

• ~50 checkpoints are marked on the new Lidar-based map of the park.

• You have 3 or 6 hours to try and get to as many checkpoints as you can.

• We will be using a Smartphone app named MapRun6 to record your visit to each checkpoint. The app will record a “punch” automatically using your GPS position.

• Results from each competitor are tabulated into a results list.

• The MapRunG app can be used with Garmin watches.

• 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 Annadel” and pick the right course - 3hr or 6hr.

• DIRECTIONS TO START: The start/finish area is located here. From highway 101 in Santa Rosa, take exit 488B to merge onto CA-12 E toward Sonoma. After 1.7mi, continue straight onto Hoen Frontage Rd which becomes Hoen Ave. and continue another 1.5 mi until Summerfield Rd. Turn right onto Summerfield, proceed 0.3 mi and then turn left onto Parktrail Dr. The start is 0.4 mi from Summerfield, on the left (north) side of the street.

• PARKING - The start is in a residential neighborhood and as such, there are no amenities and bathrooms. Parking is free but please respect the residents by parking on the left (north) side of Parktrail Dr. where you won’t be directly in front of anyone’s house. I usually find it easiest to do a U-turn at the first stop sign so I can park facing the correct direction.

• BATHROOMS - There are 2 rustic outhouses on the course and some standard bathrooms in the adjoining Spring Lake Regional Park, but nothing near the start/finish area which is in a residential neighborhood.

• 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 6-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).

• PETS - Pets are not allowed in the park.

• BE DISCREET - We don’t have a permit to use the park so try not to be too noticeable when entering or exiting off-trail areas.

MAP & COURSE NOTES

• TERRAIN - Annadel is a very interesting venue and generally considered one of the best in the Bay Area. While it is steep in places, it’s less steep overall than most Bay Area venues but does contain quite a bit more rocks than other local venues. Annadel has a variety of terrain. It’s predominantly oak forest with tall grass but also contains open meadows, conifer forests, stands of redwoods and manzanita patches. What makes Annadel unique is that the area once contained many cobblestone quarries so there are left over features from the quarry activity such as pits, depressions, knolls, cliffs, and rock fields. In October 2017, the eastern ⅔ of the park, which covers the eastern section of the course map, was burned in the Nuns fire. Since then, the burned areas have been overgrown with dense grass, berry vines, and poison oak. All the creeks in the park are dry. In September 2020, the Glass fire burned the northern part of the park just south of the Cobblestone trailhead.

• COURSE - The course was designed by Heidi Cusworth and the checkpoints were visited by Bill Cusworth. There are ~50 checkpoints varying in point value from 20 to 120 points.

• 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, 70 = 70 points, 115 = 110 points, etc. The late penalty is 10 pts/minute.

• MARKERS - Each checkpoint is marked with flagging. Most have 2 pieces of orange biodegradable flagging with “Nav-X” written on one of the pieces. 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”.

• 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 1:25000 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 1:15000 that will print onto 4 sheets of 8.5 x 11 paper with 40 mm overlap between sheets and a third pdf at 1:10000 that will print onto 9 sheets of 8.5 x 11 paper with 40 mm overlap between sheets . Both pdf maps have a 5 meter contour interval and the textual control descriptions overlaid but there is no map legend. The MapRun6 app also contains a low resolution version of the orienteering map with the checkpoints shown, but no control descriptions.

• MAP - The map was made using LiDAR data from 2013. From this data, very accurate 5 meter contours were derived. Automated vegetation data was also obtained from Lidar (more on this below). Roads and trails were imported from Open Street Map, Strava heatmap, and augmented with personal GPS tracks. Aerial imagery was used to trace fences, water features, roads, and trails. Point and line features were then imported from the old BAOC map using a long and complicated process (called Rubbersheeting).

• MAP VEGETATION: The automated vegetation from the Lidar data is very good at showing dense forest due to low tree branches. Almost all of the dark green on the map is thick manzanita and it mapped very accurately to the point where you can pick out individual manzanita trees. Undergrowth does not show up as well and does reduce runnability of the white forests a bit. In particular, the parts of the area that were burned in the 2017 Nuns fire have grown up significantly since the Lidar data was collected in 2013. This applies to the eastern half of the course and the SW ridge line, but the worst area is definitely the SE quadrant of the course. In these areas, there are some berry vines mixed with significant ankle to knee-high poison oak patches. You can mostly step around the poison oak but I attempted to show the areas that were particularly bad with the vertical green line “undergrowth” symbol overlaid on top of the auto vegetation. This undergrowth mapping is very approximate but should give you a good idea about what parts of the map to stay out of.

• OTHER MAP NOTES: Since the trails in the forests are mapped with GPS data, they are smoothed out and don’t show all the small twists and turns. I tried hard to make sure the intersections looked right. Mountain bikers are creating new trails all the time. The mapping of rock detail came from the old BAOC map which was first made in 1989. As such, the mapping of these features is a little outdated and not completely consistent with current symbols.