Mt Diablo: Sharkey-Olympia-East-Mt Olympia Trail Hike

Tuesday, September 13, 2016

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Mt Diablo began as volcanic rock beneath the surface of the Pacific Ocean was scraped into a mass between the Pacific tectonic plate and the overlying sedimentary layers of the North American plate. As ice ages affected sea levels, sedimentation continued in shallow coastal seas. About four million years ago, the older, harder volcanic material from the sea floor forced its way up from between the two plates heaving the weaker sedimentary layers up an angle. Over time, younger rock above eroded and by 2 million B.C. the older rock we recognize as Diablo’s peaks was exposed as low-lying hills. *1

Mt. Olympia is one of the park’s prime destinations, a rugged outcrop with fantastic views of dizzying canyons. This is arguably the steepest trail in the park. The first part is gentle enough, but things get a lot more challenging when you get to the flanks of Mt. Olympia – the total rise occurs in a little over a mile. There are many things to attract your attention on the way and to let you catch your breath – wildflowers well into summer, grotesquely eroded rock formations reminiscent of the American Southwest, the sequence of gradually expanding views. The climax view, of course, is from the summit itself. *2

Start by finding the slightly hidden auto-gate and head up Sharkey Road. Turn right at first road junction and soon thereafter right onto Olympia Trail. The trail briefly joins an old road. At its end make a short left jog to the posted continuation of the Olympia Trail. Follow it until you reach the exhilarating East Trail, straight up to the summit! A stiff 2,000 ft climb in 2.5 miles! *2

Begin this hike from the wide pull-out on right side of Marsh Creek Road about 1.3 miles beyond Regency Drive in Clayton. There is an emergency call box with a big blue sign-CC M 16. Enter through the unmarked park gate onto the unsigned road to the Sharkey Rd junction.

At Marsh Trail/Sharkey Rd junction: go straight and continue on Sharkey Rd; the road leads out to the open grasslands with views of the mountain peaks.

At the Wise Rd junction, turn right onto the paved road.

At the Olympia Trail junction: turn right onto Olympia and follow the narrow single track through the dense brush.

At the Olympia Trail post: continue straight through the woodlands to the open grasslands.

At the Olympia Trail post: go straight to the T junction and turn right to stay on the Olympia Trail. At the next trail post-go straight to stay on the Olympia, it continues south up along the foothill of the mountain.

At the Quarry Rd/Olympia Trail junction: go right to stay on Olympia Trail. The wide trail gently winds up the sparsely covered chaparral slopes to the next junction.

At the Wise Rd/Olympia Trail junction: go straight to stay on Olympia, it narrows on the climb through dense vegetation to the next trail post.

At the next Olympia Trail post-go straight. The steep climb opens up to fabulous far distant NE views of the surrounding valleys and mountains.

The single track trail snakes in and out of the thick brush to the open hillside with occasional views of the eastern hills and valleys.

The trail continues to traverse through dense vegetation and woodlands to the open slope.

At the East Trail/Olympia Trail junction: go left onto East Trail. The trail continues to traverse along the mountain slopes on rocky open terrain into the dense brush.

East Trail continues climbing under the shaded woodlands and chaparral-covered slopes.

The trail exits the dense brush area onto the open ridge with close proximity and views of the large rugged rock outcroppings.

The trail continues winding up along the mountain side towards the upper ridge through the scattered pines with the occasional glimpse of the valleys and mountains.

East Trail climbs out of the dense brush to the rocky ridge with fabulous open vistas!

Enjoy the panoramic views!




The rocky trail goes past a scattering of lone pines towards the next junction.

At the Zippe Trail/East Trail junction: go straight to stay on East Trail and continue up along the open ridge.

East Trail continues through the thick vegetation before exiting back out onto the ridge.

At the next East Trail post: you can continue on the trail to the summit or scramble straight up the side of the rocky slope.

Arrive at Mt Olympia-2946′ elevation. Be sure to sign the log attached to the Mt. Olympia Summit trail post to memorialize your accomplishment! *2

Enjoy the panoramic views!



Descend the summit onto East Trail and retrace steps back down the mountain.

Continue on Olympia Trail back down to the foothills.

Stay on Olympia Trail and retrace your way back to Wise Rd on the single track trail through the woodlands out to the open grasslands.

At the junction: turn left followed by another immediate left onto the unsigned Sharkey Rd. The fire road returns across the grasslands back to the park gate on Marsh Creek Rd.

Get out and experience this hike with the calf-burning climb and quad-busting descent. These trails less traveled leads to one of the mountain’s hidden beauty spots-Mt Olympia! The peak top panoramas are both dramatic and phenomenal!



5.04 Miles with 2092′ of elevation gain
Max elevation: 2916′
Time: 3.5 hours
Hike: Strenuous with steady steep climbs
Parking: There is a wide pullout area for parking about two miles beyond Regency Drive in Clayton. Look for the yellow emergency call box with the big blue sign-CC M 16
No facilities & no water.
Bring water & food/snacks-No water along the trails

Weather: Sunny & warm. Temps ranging from the mid 60’s to the low 70’s with SW winds

*The current edition “Mount Diablo Trail Map” is available for purchase at the park entrance stations, Summit Visitor Center and Mitchell Canyon Visitor Center in Mt.  Diablo State Park. They are also available at selected retail map distribution stores such as REI, Sportsbasement and on-line at MDIA’s Store.




  1. When I first saw the image I said to myself I wonder what kind of rocks they were. I scrolled down to read your description. Surprise for me. Thanks


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