The Slide Mountain Lookout Trail isn't near many other hikes and is a bit of a trek to get to, but it is well worth the effort. The hike is unique in a lot of ways. First, you'll hike through the dramatic Piru Gorge, but you'll do it on an abandoned highway, giving the stretch a surreal post-apocalyptic feel. Then you'll sweat as you climb over 2000 feet on dirt trails toward the summit. Along the way, you'll get spectacular views into the rugged backcountry of the Sespe Wilderness. At the top is a fire lookout, manned by volunteers and only accessible by hiking.
In this Guide:
Video and Turn-by-Turn Directions to Slide Mountain Lookout
When planning, always check the park website and social media to make sure the trails are open. Similarly, check the weather and road conditions.
This is one of the only hikes where you start in Angeles National Forest and end in Los Padres National Forest.
Where is Slide Mountain Lookout?
This hike starts in the northwest section of Angeles National Forest, off I-5 when you head north out of the LA area. You'll be sharing the trailhead with anglers who are visiting Piru Creek. Use this trailhead address: Frenchmans Flat Campground, Castaic, CA 91384
The trailhead is easy to find because the road dead-ends into this gate.Make sure that you park in the actual parking spots, and not by the "no parking" signs that are closest to the gate.
Because there are toilets here, you need to display a parking pass. I use my National Parks pass, and you can also use an Adventure Pass.
There's a toilet down below in the Frenchman Flat Campground, but there's another one a short distance down the road that's easier to get to.
Gear For the Hike
You can go with your standard hiking gear here, there are no curve balls. I found that I even had 5G cell reception for most of the hike. The hike is exposed and can get hot in the summer, bring 2-3L of water. You'll also want to bring some insect repellant. The ideal time to visit in in the cooler and windier months when the insects and heat are not an issue.
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The markings are minimal also the route, but there are these mile markers on the trail. Note that the mileage starts from the beginning of the trail / end of road portion.
The first part along the road feels flat, and then you have a steady climb up to the top. The gradient isn't too bad and you can usually get into a nice groove here.
3D Map
The first 1.5 miles is along the old (closed to traffic) US-99, through Piru Gorge. Then you climb up on the Slide Mountain Trail.
Hike Brief
The beginning of the hike follows old US-99 through the spectacular rock formations of Piru Gorge, beautiful enough that they used to make postcards of it, as you see in this one from the 1930s.
Before there was I-5, there was US-99, the north-south route up the west coast that was as iconic as Route 66. This hike starts along this road, first built in 1915, and widened to what you see today in 1951, then abandoned in the 1960s when the nearby "ridge route" of I-5 was opened.
The dramatic and layered rock formations result from movement along the San Gabriel Fault, which loosely follows the same route as the road.
The road also follows Piru Creek (native Tataviam word for the reeds that grow along the creek), a popular fishing spot. The creek by Frenchmans Flat is stocked with rainbow trout each year.
When US-99 was closed, Piru Creek was dammed and Pyramid Lake was created in 1972, which also submerged portions of US-99. Today Pyramid Lake is a recreation area and reservoir.
The Slide Mountain Fire Tower was built in 1969 when Pyramid Lake was being constructed. Today it's on the National Historic Fire Lookout Register and is manned by volunteers during fire season. Volunteers usually spend 1-2 days per month at the tower. And if there's a volunteer there, they'll sometimes let you visit the inside of the tower.
Start the hike by heading through the gate.After a minute on the road, there's a toilet on the right.
Keep your ears open for the occasional utility vehicle driving on the road.
You'll reach the bridge over Piru Creek. The righthand side of the bridge was built in 1932, and the lefthand side was built in 1951 when the bridge was widened to four lanes.It's worth taking a look down into Piru Creek, which is usually clear enough to see to the bottom of. The waters in Pyramid Lake ensure that Piru Creek flows all year.
The creek is officially designated as the Piru Creek Wild & Scenic River, a protected area since 2009.
There's also an angler sign-in just past the bridge.Keep your eyes open on the slopes up to the left, where you can catch a glimpse of the fire lookout in the distance. This is the only time that you can see it before you get to the top.As you continue, look for a concrete waterfall on the right. The trout below the fall are stocked, any trout caught above this are wild.Continue down the road as it winds to the left.It's easy to see the San Gabriel Fault action in the cliffs surrounding you.When you get to this trout area sign (on your right), you're almost at the trail turn off.Keep your eyes open for a white gate on the left.Hike through the gate and leave the road behind.Now you start the business end of the climb. It's uphill but not too steep.Look back as you climb to see the walls of the Pyramid Lake Dam.The trail continues winding up. At this point it's wide, but nothing like a standard Forest Service road.And as you ascend, you'll start to be able to see into Pyramid Lake.At about 2.7 miles in there's a clearing and the trail makes a hard left.And now is a proper singletrack trail.The trail winds back and forth, giving you a variety of views.And soon Slide Mountain comes into view.When you get to the saddle, make the right to continue.From the saddle to the peak, prepare for breathtaking views into Los Padres National Forest and the Sespe Wilderness. The area is dramatic, wild, and largely untouched by trails or human imprints. The big mountain off the right is Dome Mountain in Ventura County.
The Sespe Wilderness, created in 1992, includes the Sespe Condor Sanctuary, which is off-limits to humans. I've seen condor on this hike, keep your eyes open, and maybe you will too.
The trail seems to be a little less steep than before as it follows the ridge.Once past the saddle the trail zigzags back and forth over the border into Los Padres NF.And as you wind around, you'll start a section of wide switchbacks.And then you'll come around to the east side again, with more great views.Then you'll wind back over to the Los Padres NF / west side again.And soon the tower will come into view ahead.And here you are, the Slide Mountain Fire Lookout.There's a visitor register.Most of the time you can climb up to the gangway around the tower. Be respectful, especially if there's a volunteer here.The inside of tower is pretty cool.And lastly, there's a porta-potty that has the best views ever.
Hi, I'm Cris Hazzard, aka Hiking Guy, a professional outdoors guide, hiking expert, and author based in Southern California. I created this website to share all the great hikes I do with everyone else out there. This site is different because it gives detailed directions that even the beginning hiker can follow. I also share what hiking gear works and doesn't so you don't waste money. I don't do sponsored or promoted content; I share only the gear recommendations, hikes, and tips that I would with my family and friends. If you like the website and YouTube channel, please support these free guides (I couldn't do it without folks like you!).