September 25, 2015

Top of Dry Creek-- Sunday, October 4– An Entirely New LiDAR Map

Join us for a new orienteering adventure at the top of the Dry Creek drainage. This new terrain is above the Boise Ridge Road, below the Shafer Butte Road and bounded on the west by Bogus Basin Road. It offers a variety of vegetation and other features in an area mostly void of trails and other man made elements. Like our Bogus Basin map it has challenging elevation changes and brush obstacles to navigate around. And like our Gold Rush map it has some large areas of runnable Ponderosa Pine forest. Unlike our Bogus Basin map it has reliable contours generated from LiDAR. It is just 12 miles up Bogus Basin Road.

We are offering three courses. Because the map field work is labor intensive, the mapped area is still relatively small. The advanced course will probably be less than 5k. However, that could be a tough 5k because of the elevation changes and obstacles to navigation. A shortcut will reduce the distance and elevation gain for the intermediate course.  Novice orienteers will venture entirely off-trail along linear features or will search for large prominent features on a course with many short legs. Due to the absence of trails there will be no truly beginner course. It will be necessary for participants on the novice course to identify features like boulders, spurs and re-entrants on the map. If you are a novice and unfamiliar with orienteering map symbols, the meet directors and experienced orienteers will gladly give you a brief explanation before you depart on your adventure. As this map develops and the representations of vegetation become more accurate, vegetation will play an increasingly important role in navigation.
All three courses (novice, intermediate, and advanced) begin and end on the Boise Ridge Road near its intersection with Bogus Basin Road.
Because cut branches on the ground and steep slopes often make the footing unstable you should bring sturdy shoes and good judgment about when to be cautious.

In the desire to minimize waste and save myself some printing expenses, please RSVP to me no later than Thursday October 1 with your name and intended course choice (and if you want an extra map or two for a larger group.)  My email is jnm2870 AT cableone DOT net.  If you decide to show up impromptu, I expect to have a few blanks on hand and you will get to copy your course the old school way. When the maps are gone, they are gone.

Who: Orienteers of all ages, novice to advanced.
When: Sunday October 4. Courses will be open for starts from 10am – 12. Courses close at 2 pm. You may arrive within this window to try a course, as participants start separately a few minutes apart.

Finish and Parking Location: Boise Ridge Road

Be advised that there is no parking area at the start. Orienteers will need to park at wide spaces on the Boise Ridge Road ensuring that traffic can pass safely. Accordingly, you might have to walk to the start. There is an area to use for parking about 400 meters up Bogus Basin Road. Because of the danger of fire exercise caution to avoid parking in dry grass.

Restrooms are not available. You are responsible for your own water.
Format: Classic. 
Cost:  $10 per person/team, $5 for a single junior, free to CTOC members (more info here)
You may want to bring: a watch, a compass, a snack, a whistle and a cell phone. (Some compasses will be available to borrow.)

A word about LiDAR: Several government agencies have acquired high resolution mapping data for land management. In Idaho many of the LiDAR projects are undertaken for hydrology studies. The process involves a low altitude GPS guided laser scan resulting in a digital elevation model with accuracy sometimes in a range below ten centimeters. These data have been made available free to the public in many cases. We have BSU's Dry Creek Experimental Watershed to thank for the reliable contours on this map.

A Finnish orienteer developed free software to convert LiDAR data into contour maps with vegetation colors. Using his software we have found the contours to be extremely accurate. Sadly, we have not been able to optimize the vegetation mapping parameters to the point where there is usable detail. Consequently, mapping vegetation and other features requires extensive field work in addition to drafting using computer software.

Directors: John Murray and Jerry Stewart

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