Shell Ridge Open Space

Costanoan Trail–Flat Top Trail, 3 sights

4.5 mi · ▲ 1,093 ft · 2 hr 3 min

Costanoan Trail–Flat Top Trail, 3 sights is a 4.5-mile out-and-back in Shell Ridge Open Space near Walnut Heights, CA. It climbs 1,093 ft, with sections as steep as 19% grade, and is mostly dirt. It scores 59/100 on the Ambleway Wildness scale: backcountry feel.

Elevation

0 mi295 – 840 ft · steepest grade: 19%4.7 mi

Getting there

Trailhead: Unnamed 37.88769, -122.01444
Nearest town Walnut Heights, CA

Directions

AMBLEWAYwww.ambleway.com

Costanoan Trail–Flat Top Trail, 3 sights

4.5 mi · ▲ 1,093 ft · 2 hr 3 min

Elevation 296–841 ft

Out & Back · Shell Ridge Open Space

Trailhead: 37.88769, -122.01444

Weather Aug 3: Mostly clear, high 101°F / low 63° · precip 0% · wind 2 mph · sunrise 6:14 AM · sunset 8:16 PM

  1. Start at the trailhead, heading SE.
  2. 200 ftBear left onto Sugarloaf-Shell Ridge Trail, heading E.
  3. 0.4 miTurn right onto Briones to Mt. Diablo Regional Trail, heading E.
  4. 0.2 miTurn left onto Ridge Top Trail, heading NE.
  5. 0.7 miTurn right onto Costanoan Trail, heading SE.
  6. 150 ftTurn left onto Flat Top Trail, heading NE.
  7. 0.2 miTurn left, heading N.
  8. 0.2 miTurn right, heading NW.
  9. 0.2 miBear left onto Costanoan Trail, heading NW.
  10. 0.4 miReach Sugarloaf-Shell Ridge Trail, then turn around and head back the way you came.
  11. 0.4 miBear right, heading SE.
  12. 0.2 miTurn left, heading S.
  13. 0.2 miTurn right onto Flat Top Trail, heading E.
  14. 0.2 miTurn right onto Costanoan Trail, heading S.
  15. 150 ftTurn left onto Ridge Top Trail, heading S.
  16. 0.7 miTurn right onto Briones to Mt. Diablo Regional Trail, heading S.
  17. 0.2 miTurn left onto Sugarloaf-Shell Ridge Trail, heading W.
  18. 0.4 miBear right, heading SW.
  19. 50 ftArrive back at the trailhead.

Each distance is the walk from the previous step. Tap a step for a map of its junction.

Trail surface

86% dirt14% unspecified

Weather

Mostly clearTemperature 101°F63°
Precip0%Wind2 mphUV8Humidity38%
Hourly temperature
105°60°
Sunrise 6:14 AM12 AM3 AM9 AM12 PM3 PM6 PMSunset 8:16 PM
Tue 91°63°
Wed 89°55°
Thu 98°56°
Fri 103°61°
Sat 103°59°
Sun 102°58°

Sunset

The best sunset spot on this hike is 1.2 mi in (~43 min). Leave by 7:13 PM for the 8:16 PM sunset. Back at your car by 9:01 PM, after dark — bring a headlamp.

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