I did get out after work on Friday, around 5:30, and hiked up to the Historic Trail via the West Ridge.
1. I brushed the section between the West Ridge and the bend just above the Nike pipeline, focusing on over-arching blackberry vines and shoulder-height elderberry bushes on the upslope. It should last us into winter. I left it kinda narrow in places, to reduce the temptation for bicyclists to speed toward that corner where people ride high up the bank). But people will no longer be forced off the outside edge of the trail. I dug out (rather than trimmed) some of the elderberry that had taken root right at the nose of the upslope; it can only grow back into the trail if I were to clip it.
2. Closer to the West Ridge there were several patches of mud and/or tire tracks in the center of the trail. Rock or gravel tread was not far beneath the mud. I scraped off the mud with the teeth of my McLeod, then took the teeth and blade to the outer edge of the trail, digging up the accumulated organic material and scraping it lower than the center of the trail (generally down to gravel or old trail tread). This should help things drain in heavy fog-drip or rain, and give the fine organic particles a place to flow off the trail again. Nothing wrong with what we did originally, it's just that the center of the trail has packed down a lot more. This is the perfect time to do it; it will probably also be plenty wet in winter.
Both tasks can be done on nearby stretches of trail. I would also want to eventually push back the wall of vegetation above this stretch of trail, so blackberry vines have a harder time arching 10 feet overhead (and there are some nice natives among the blackberry vines).