On the morning of Wednesday, March 13, signs were placed on the trail that skirts the east fence of JPL (west of the stream), announcing a temporary closure while a new parking structure is built. The signs indicate that the closure will extend through the summer of 2014 and advises trail users to use “other existing trails” to avoid the construction site.
In the 20 years I've used this trail for hiking and biking, JPL has done far more to undermine the trail (literally, by its unchecked storm runoff) than to maintain it or to facilitate its use. The suggestion to use “other existing trails” therefore seems cynical, since the only other established trail is the one that would reach the JPL bridge by way of Devil's Gate Dam — a three-mile detour. Granted, it is possible to cross to the east JPL lot by way of an informal route that heads straight across the Arroyo, but this other trail crosses the Arroyo by way of an un-maintained ford that is passable when dry but has been hazardous during any time of heavy rain and runoff.