Hike Thunder Spring and Chimney Flat Loop

Rate this Adventure San Diego Upper Doane Valley Parking Area

Added by Torrey Schaefer

Hike San Diego's best spot for lush pines, crisp air, and true season presence.

Palomar Mountain is the hidden gem of San Diego. Well, not so hidden per se- but most don't know that the little climb up the mountain can transport you from the prevalent brush-filled terrain of SD to a lush, diverse forest.

The great thing about Palomar is that every day you visit could be completely different from the last. If you go in the early morning on a late fall day, chances are you will be engulfed in a thick, eerie fog. Or on a late spring day, it is clear and lush. Winter, snow. The mountain is ever-changing which means that these hikes are, too.

This is one of my favorite trails within the state Park, although there are plenty more like Lower Doane Valley. It is quick, yet will get your heart pumping and take you across the different topography of the mountain.

The trailhead starts on the right side of Doane Lake. The first mile ascends the mountain through lush dogwood pines. It is not a steep climb, but instead a consistent grade. After this portion of the hike, you will emerge in a valley which, depending on the season, will be dotted in red fern or a golden yellow. I always seem to spot deer at this section of the hike- I have run into them more times than not.

The trail then takes you back into the tree line as you make your descent down the hill. Once at the bottom, you will parallel Upper Doane Valley and Thunder Springs, which is usually always running to some degree, as you make your way back to where you started.

Pack List

  • Permit
  • Snack
  • Camera
  • Cold beer for relaxing after
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Skill Level:



Year Round

Trail Type:



4 Miles

Elev. Gain:

900 Feet


Picnic Area

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Added by Torrey Schaefer

either at the beach or in the mountains

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