There is an expansive network of trails within the thousand foot ridges that make up the Irish Hills southwest of San Luis Obispo. While the regions notable chain of volcanic peaks gather greater attention from hikers, you can actually get a great view of the Morros from the Irish Hills, with smaller crowds. From Prefumo Canyon, one of the two main trailheads in the Irish Hills Natural Reserve, take Mariposa Trail to Morro View, a landing on the hillside where you can gaze seaward to the westernmost Morro, Morro Rock in Morro Bay. To the viewpoint and back is 3.15 miles round trip with 850 feet of elevation gain. Because there are so many trails through the Irish Hills, several alternative routes to Morro View are possible, including a 3.5-mile round trip hike from a less-used trailhead at the end of Sterling Lane.

Don’t feel like warming up? Great. The hike gets down to business with a steep climb through an oak forest. After half a mile, Mariposa Trail meets Bog Thistle Trail. At the end of the hike, take this track back to the trailhead past a patch of rare thistle found only around San Luis Obispo. For now, continue up the trail through low chaparral and grasses that allow broad views over Los Osos Valley, Laguna Lake, Bishop Peak, Cerro San Luis, and much of San Luis Obispo County. The unassuming Irish Hills pack a powerful punch in the view department.

Mariposa Trail and the Morros beyond the Irish Hills

There are several junctions on the route to Morro View thanks to all the trails dissecting the Irish Hills. Fortunately, every junction is well marked (with words and pictures!). Each trail junction and turn is listed below, but following signs labeling each trail will be easier than remembering these steps:

1. At 0.15 miles stay to the right through a junction with a neighborhood footpath.
2. At 0.37 miles stay to the right again at a junction with Woodland Trail
3. At 0.51 miles stay to the left at a junction with Bog Thistle Trail
4. At 1.04 miles go straight through two junctions with Rudata Vista Trail and the Mine Trail
5. At 1.28 miles turn right on Morro View Trail
6. At 1.48 miles turn left to stay on Morro View Trail
7. At 1.61 miles turn left again to stay on Morro View Trail
8. At 1.66 miles reach the top!

There are a few rocky ascents along the trail. Open vistas will inspire you to reach the 1,030-foot viewpoint, where on a clear day, the whole chain of rugged peaks is visible as far west as the iconic pointed rock in Morro Bay. There is an “End of Trail” sign at the terminus of Morro View Trail to let you know when you’ve reached the top. As a bonus, if you step behind the brush just west of the sign, you will find a small cave going straight down into the earth.

Hiking Mariposa Trail above Laguna Lake and Cerro San Luis

Enjoy the view, and then retrace your steps toward the trailhead. The detour down Bog Thistle Trail comes 1.15 miles from the top. From there it is a third of a mile to the trailhead past a patch of Chorro Creek Bog Thistle, a rare thistle found only in San Luis Obispo County. If you are not satisfied with this 3.15-mile trek in the Irish Hills, you may delve deeper on trails exploring canyon and abandoned Chromium mines. Check out Froom Creek Trail for another hike in the Irish Hills. No fee or permit is required to hike in the Irish Hills, so get out and enjoy.

To reach Morro View from the trailhead at the end of Sterling Lane, follow the purple line in the map below. Take the first right on Mariposa Trail, and follow this service road up the mountain for 1.4 miles to the turnoff for Morro View Trail for a 3.5-mile round trip hike with 900 feet of elevation gain.

To get to the trailhead: Take the 101 Freeway to exit 200, Los Osos Valley Road, three miles south of downtown San Luis Obispo. Drive northwest on Los Osos Valley Road for 1.5 miles and turn left on Prefumo Canyon Road. After 0.9 miles, turn left into the parking area for the trailhead. Mariposa Trail begins from the end of the lot.

Use the map below to create your own directions:

Photos

 

                         

These photos were taken in July and December of 2011. Click to enlarge.

 

Nearby Trails

 

	Froom Creek Trail This 3-mile loop explores a canyon on the east side of the Irish Hills, ascending 500 feet to a nice view over Laguna Lake, Cerro San Luis, and Bishop Peak.
	Cerro San Luis This 4-mile hike summits one of the Nine Sisters just west of downtown San Luis Obispo.
	Cerro San Luis from Laguna Lake Park This 5.7-mile hike reaches the summit from a nearby park.
	Lemon Grove Trail This 2.2-mile loop visits a historic lemon grove on the eastern slopes of Cerro San Luis.
	Bishop Peak This 3.5-mile hike ascends 950 feet to highest summit in the Nine Sisters, offering excellent views of San Luis Obispo and the surrounding Morros.
	South Hills Ridge Trail This 1.5-mile round trip hike ascends 450 feet to the highest point in a cluster of hills near downtown San Luis Obispo, offering fine views over the city and surroundings.
	Islay Hill This 1.8-mile round trip hike climbs 550 feet to the top of San Luis Obispo’s easternmost Morro.
	Johnson Ranch Loop This 2.5 to 3.7-mile loop explores a grassy open space just south of San Luis Obispo.
	More hikes in San Luis Obispo Explore other trails around San Luis Obispo including Morro Bay State Park and Montaña de Oro State Park.

 

More Info

 

Irish Hills Natural Reserve aerial map and brochure on on ci.san-luis-obispo.ca.us

A map of Irish Hills Natural Reserve on slocity.org

Irish Hills Natural Reserve on slocity.org