This 4 mile out-and-back hike of Cerro San Luis begins at the Lemon Grove Loop Trailhead in my old hometown of San Luis Obispo, CA. This hike gains 1082ft to reach the 1292ft summit of Cerro San Luis for commanding views of the Central Coast. Cerro San Luis is one of the “Nine Sisters”, or Morros, a series of peaks that run from San Luis Obispo to Morro Bay. The Nine Sisters were created by volcanic plugs of magma some 20 million years ago. On a clear day, you’ll be able to see many of the Nine Sisters as a chain of peaks stretching out towards the Pacific Ocean.
Directions And GPS Tracks:
- This hike of Cerro San Luis begins at the Lemon Grove Loop Trailhead, located in San Luis Obispo, CA. A large dirt parking area is accessible just off of HWY 101 using the Marsh St exit. See on Google Maps.
- Download GPX
- See track on Strava
Key Points:
- Distance: 4 miles roundtrip
- Elevation Gain: 1082 ft
- Minimum Elevation: 198 ft
- Maximum Elevation: 1292 ft
- Time: 1-3 hours
- Difficulty: (2/5)
- Dog Friendly: Yes
- Permit Required: No
- Parking: Free parking located in a dirt lot off of Marsh St.
- Weather: This trail can be hiked year round. The weather in San Luis Obispo is pretty close to perfect most of the time, but be mindful of your footing during the rainy season.
- Trail Condition: Fire road and a few stretches of rutted single track
- Cell Phone Reception: Very good
Make sure to hike with the right gear. See my current hiking gear list.
Hike Map And Elevation Profile:
Hike Description:
There are quite a few trail options to reach the summit of Cerro San Luis, so make sure to be vigilant and take the correct turns.
0.0 Miles (198ft)- Starting from the dirt parking area near the trail, head north towards Cerro San Luis which you’ll see in the distance. The trail starts out smooth and level, a major reason this is also a popular trail for mountain bikers.
0.6 Miles (579ft)- You’ll reach a junction for the Lemon Grove Loop Trail and the “M” Trail. Stay left and continue on the the “M” trail.
Shortly after passing that junction, you’ll reach another with signage for the “M” Trail. Stay left here and continue towards the Cerro San Luis Fire Road.
*There is a big concrete “M” on the side of Cerro San Luis that can be seen from below. You can take this short trail offshoot for a close up look if you want to add a little extra hiking to this outing.
After staying left at the second junction of this hike, you’ll pass through two gates. On the other side of the two gates, you’ll be hiking on the Cerro San Luis Fire Road. The beginning part of this hike was on land owned by San Luis Obispo. From this point, you’ll be on land owned my the Madonna family. They allow free public access, so no need to worry.
The Cerro San Luis Fire Road wraps around the west side of the summit block, before taking you to the top. It’s at this point that you’ll get your first views of The Nine Sisters, with Bishop Peak right in front of you.
1.5 Miles (1000ft)- You’ll reach a junction for the Cerro San Luis Fire Road and the Baby Rock Garden Route. Both routes head towards the summit, but the Baby Rock Garden Route is more enjoyable in my opinion. Take a right at the junction to hike the single track of Baby Rock Garden.
As the Rock Garden Route tops out, you will rejoin the Cerro San Luis Fire Road. Once again, you can make a choice on which route you’ll take to the summit. The fire road on the left and single track to the right will both take you there.
Just shy of the peak for Cerro San Luis, you’ll see a stage platform that is used for ceremonies on holidays like Easter and Christmas. There is also a stand mount on the actual summit to hold a cross on Easter and a tree with lights during the Christmas season.
1.9 Miles (1292ft)- After engaging in 10ft of boulder hopping, you’ll be standing on the summit of Cerro San Luis.
From the summit, you’ll have commanding views of San Luis Obispo and The Nine Sisters. Take your time and enjoy it.
For your descent, you can follow the same trail that you hiked up, or mix in a few of the fire road sections to make things a little easier on the legs.