This event is in the past.It took place on May 31, 2026 at Sibley Volcanic Regional Preserve.

Butterfly Spring: McCosker Loops 1
Mountain Spot
Butterfly Spring: McCosker Loops 2
Butterfly Spring: McCosker Loops 3
Butterfly Spring: McCosker Loops 4
Butterfly Spring: McCosker Loops 5

Butterfly Spring: McCosker Loops

May 31 at 9am

At Sibley Volcanic Regional Preserve

Oakland

🌀"The labyrinth was awesome" (Google review)
🪨Naturally occurring obsidian stone deposits here
🐕Popular with local families walking dogs

When the hills turn emerald in spring, Sibley Preserve erupts with wildflowers and butterflies. Wander gentle trails past volcanic outcrops and ancient obsidian deposits, with valley views from every ridge.

Spring wildflowers
Butterfly watching
Volcanic geology
Family-friendly hikes