My mom and I took a trip the other day on the trail that winds up the northern part of the Arroyo Seco behind JPL, where we saw considerable damage from this winter’s heavy rains and flooding. Though the trailhead is posted as closed due to the Station Fire destruction of summer 2009, you can still walk a long way before damage from flooding becomes noticeable. The hike was beautiful thanks to the rains, as the river was running fast where it used to be dry, even creating small waterfalls in some places. About a half a mile in, just before reaching the small compound of park ranger houses, the trail is posted again for fire damage, but this time it is physically blocked off with caution signs and small wooden guard rails.
We thought twice before crossing this blockade, but figured there was little risk since the day was sunny, without any chance of mudslides or sudden rushing water. We wanted to see what was so drastic about this damage. And we got our answer—just a few hundred yards passed the caution sign, the trail was completely gone. I hadn’t been on this walk in nearly a year and I didn’t recognize anything. What used to be a lightly forested trail had now opened into a wide valley, with the river splitting up and meandering along smaller channels created, no doubt, by swift water and debris. Fallen trees were scattered throughout this wide open space, and a worker was hard at work cutting one up and loading it into his truck.
We did not continue far up the washed-out stream bed, but it seemed perfectly safe (as long as you don’t mind loose rocks and water crossings). We saw no other people scrambling around, so it seemed that everyone else on the trail that morning had chosen to actually obey the posted signs. Nevertheless, I would certainly recommend taking this walk and going as far as you feel comfortable, whether it’s just to observe the rarity that is loud, flowing water—or to journey farther and marvel at the sheer strength of this La Niña season.
The JPL walk trailhead is located at the very western end of Altadena Drive, and there is parking on the street.