Mt. Lowe Summit Loop from Cobb Estate

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Features River/Creek · Views · Wildflowers · Wildlife

This 13 mile run will take you from the top of Lake Ave in Altadena to the Summit of Mt. Lowe by way of several well-known trails written up elsewhere on this website. It offers varied terrain, great views, and interesting historical markers along the way. It is also fun to do at night, to look down on the lights of Los Angeles County!

Bring at least 3 liters of water for this loop, more on hot days.

Footing is fairly smooth on Lower Sam Merrill Trail 12W14.1. Footing is steep in places along Castle Canyon Trail #12W28. Very rough footing at bottom of Mt. Lowe East Trail 12W14.3A. Loose footing from heavy usage along bottom two thirds of Middle Sam Merrill Trail 12W14.2

Park your car at the top of Lake Ave, and follow signs for Lower Sam Merrill Trail 12W14.1 to Echo Mountain.

After passing the water fountain and a dry stream bed, Lower Sam Merrill Trail 12W14.1 starts to ascend the front of Echo Mountain. It is a constant uphill trail, and there is little shade available.

At 2.7 miles, you'll reach the flats of Echo Mountain and the Echo Mountain Trail 12W14.A. Bear right at this T-junction, heading east about 0.1 mile to the Middle Sam Merrill Trail 12W14.2. Take note that this is the trail you'll descend on your return from the summit of Mt. Lowe.

Just a few feet farther east towards the ruins of the Old Echo Mountain House is the start of the Castle Canyon Trail #12W28. Take this trail for 1.8 miles, which starts on a gentle contour but eventually starts climbing the steep walls of Castle Canyon towards Inspiration Point. This trail is well shaded and steep in places, but cooler as a result and offers a nice respite on hot days.

After 1.8 miles, you reach Inspiration Point, a shaded pavilion with picnic tables and old way-finders, pointing out places of interest in the sprawling Los Angeles County below. On a clear days, this place truly offers fantastic views making it was to see how it got its name so many years ago.

Look north and you can now see the summit of Mt Lowe. Go northwest along the Muir Peak Road #2N50.A for about 0.3 miles and you'll reach an intersection with the Mt. Lowe Road #2N50 where the top of the Middle Sam Merrill Trail 12W14.2 disappears into the woods on your left. This is the trail you'll descend down on your return to this very spot after you summit Mt. Lowe.

Turn right, heading north along the Mt. Lowe Road #2N50 for about 0.1 miles until you come across an old metal sign saying "Mt. Lowe East." This is the bottom of the Mt. Lowe East Trail 12W14.3A. Over the next 0.3 miles, it is a hard scramble over loose rock and gravel as you ascend steeply, until you reach a trail that bears off and down to the left. DO NOT TAKE THIS TRAIL, but instead bear right and ascend up across a series of switchbacks and you'll find the trail now starts to wind its way east around the front of Mt. Lowe itself.

1.0 mile after leaving Mt. Lowe Road #2N50, look for a metal sign pointing to Mt. Lowe Summit and a trail bearing off to the left. Take this trail as you now start the final ascent of Mt. Lowe on the northern side. There could be snow along this section of the route in winter.

0.3 miles along (6.1 miles total) is a USFS trail stake and the intersection with the top of the Upper Sam Merrill Trail 12W14.3 (Mt. Lowe West Trail). Bear left and up to the Summit of Mt. Lowe. The actual summit is to the left after you reach the clearing. To the right is a bench to sit on to enjoy fantastic views reaching from Mt. Baldy to South Bay on a clear day.

Descending, bear left at the USFS stake down Upper Sam Merrill Trail 12W14.3 (Mt. Lowe West Trail). This trail winds down the west side of Mt. Lowe to Mt. Lowe Road #2N50, affording fantastic views to the western range. In the winter, when there is snow on the ground, look for mountain lion and deer tracks.

Once you reach Mt. Lowe Road #2N50 bear left and in 0.2 miles you'll be back at the intersection at the top of Middle Sam Merrill Trail 12W14.2. The start of this trail winds along the contour of the west side of the Front Range, and is well shaded for the first 0.8 miles. At 0.8 miles (8.6 miles total), round the front of the Front Range and for the rest of the route down the Middle Sam Merrill Trail 12W14.2 you are afforded wonderful views of Los Angeles. This is the reason why you want to do the loop in this direction, so you have the views IN FRONT OF YOU as you run!

2.5 miles after leaving the Mt. Lowe Road #2N50, you'll be back on Echo Mountain. Turn right (west) and then bear left and down the familiar Lower Sam Merrill Trail 12W14.1, returning to Lake Ave.

In the spring, one can find all sorts of flowers in bloom along all of the trails. Castle Canyon Trail #12W28 and the top of Middle Sam Merrill Trail 12W14.2 offer lots of shade under big oaks.

This loop takes you along part of the historical Mt. Lowe Railway, and a short diversion at Echo Mountain will take you to the ruins of the Echo Mountain House, or White Castle, built by Thaddeus Lowe in the late 19th century.