I started paying attention to this phenomenon a little over a year ago after viewing some videos created by Dane Wigington.
Speaking of when this ends, I live in the Sacramento region in Northern California and after having seen many trails on a daily basis from last summer until late this spring, I have observed minimal to zero activity since early June until just recently in late August. In the last ten days or so, I've noticed the trails starting to increase again.
Any thoughts on the decrease/halt in activity and then the recent increase?