Del Valle Wilderness Scramble
Del Valle Regional Park
Date: (Sun.) Apr. 7, 2013
Location: Livermore, CA
Event Directors: 
- 505.310.8645, - 209.928.4771, - 209.928.4771
Course Setter: Damian Swift
Type: C; Teams of 1 to 5 find up to 30 checkpoints in up to 3 hours in this scenic Bay Area park
Course Setter's Notes
By Damian Swift
Park and Terrain
The event will use the east/north side of Lake Del Valle, starting at the East Beach area. The terrain is a series of spurs and valleys running away from the lake, mostly grassy and runnable woodland. The hillsides might be steep, and the valley bottoms tend to form erosion gullies that might be deep and cliffy. It's a really nice time of year to run at Del Valle, as the grass is green with plentiful wildflowers.
There seems to be very little poison oak in the areas we're using, and we haven't noticed any ticks so far. Supplies of both will be available at the start for those who insist on the complete BAOC experience. There are mountain lions in the park, but we're unlikely to encounter them. Your intrepid mappers/vetters have, however, seen rattlesnakes close up, so watch who you're stepping on. Cattle are grazing in the park, with calves, so don't come between a mother and etc. The park ranger requests that we take care to close gates. Other wildlife noted: vultures, blackbirds, deer, bobcat.
Map
The Del Valle map is brand new, some might say not even that. It's based on LIDAR contours processed by Bob Cooley, at 5 m interval, with other features added by me. The contours are busy at Del Valle, and in some cases it was unhelpful to indicate gullies with a separate symbol where the contours already showed them. Similarly, marking earthbanks in some cases obscured the fine detail of the contours. We have used symbols to indicate cliffs and gullies where needed to emphasize hazards and obstacles, but bear in mind that closely-packed contours might in general give a steeper slope than your comfort zone. The deeper erosion gullies might have impassably steep sides, while being flat enough to walk along — the rate the gully cuts contours is a good guide.
We put most effort into mapping the area we're actually using, starting with major trails and obstacles. Other areas, such as the lake shore, don't have all details added yet. Similarly, you might well come across the occasional rock or dead tree that isn't marked on the map. The major trails should all be mapped and correct. There are many minor game trails whose distinctness varies seasonally — some are unmapped. Thanks to the Petersen family for field-checking; volunteers are welcome for more!
On the Del Valle map, a green "o" symbol represents a "distinctive tree": a living tree, with no other trees nearby similar in size to the one indicated by the symbol. Larger trees might be denoted as woodland. A green "×" represents a standing, dead tree; a brown "×" represents a fallen, dead tree. I saw several trees that caught the eye as dead, but turned out to be mostly living with a side of dead branches. I considered them as living. My intention was to identify clearings if the space between the trees was more than the typical size of a tree in the vicinity. In areas I mapped early, I had to guess how the trees would look once the leaves started to come out, and the map won't be perfect. Smaller, isolated bushes might not be marked on the map.
A blue "×" denotes a water feature, such as a faucet near a camp or picnic site. One of these has a water-stop symbol beside it on the map: it might be useful for this year's event.
Thanks also to Rex Winterbottom for advice on making the map.