The Historic Flume Trail is actually a small part of a 37 mile system that was built in the late 1800's to transport water from Lake Cuyamaca to the El Cajon Valley. We've covered another section of the flume on this page. You can read the entire backstory of how the flume came to be on that page.
We did this hike in winter when the weather was mild and the hillsides were lush and green. The views of El Monte Preserve and mountainscapes was breath-taking. It was so much fun finding the little tunnels! They looked like troll homes to me.
The hike begins with multiple switchbacks up the hillside making it a gradual climb instead of a straight shoot up. While we were up here we hiked to Lake Jennings as well and scoped out the lake a bit.
A glimpse of the flume:
The trail begins with a lot of switchbacks as you climb the hill. Eventually it flattens out:
This is a shot peeking into the tunnel. You cannot actually get inside them:
That orange stuff on the right is called Witch's Hair and is a parasite:
Check out those views!
View of the flume from ground level: