Bay Nature Hike: Summer Blooms in Black Diamond

This event is inspired by Bay Nature's Summer 2025 piece, Why Some Flowers Bloom In the Dead of Summer, by Ken-ichi Ueda

Join Bay Nature and Ken-ichi Ueda for a hike at Black Diamond Mines in search of summer flowers on Saturday, September 6 from 10am - 12:30pm. Wildflowers? In summer? In the Bay Area?! They're real, and we'll be looking for them. We'll start at the upper parking area at the end of Somersville Rd and take the Stewartville Trail up to the Ridge Trail and return via the Chaparral Loop Trail. On the way we'll look for tar weeds, gum weeds, match weeds, vinegar weeds, and anything else that manages to flower during the dry season, weed or otherwise. This hike is free for Bay Nature Members.

Meet Your Hike Leaders:

Ken-ichi Ueda is an angry old man from Oakland who likes looking at plants. Hairy flies and offensive glandular aromas are important parts of his love language. He is also one of the cofounders of iNaturalist.

Cat Chang learned Mālama ‘āina from her Native Hawaiian family. The Bay Area is her home while continuing caring for the land. In her everyday work, she focuses on buildings and landscapes supporting regenerative ecological, agricultural and cultural footprints within cities.

Meet up location: Black Diamond Mines Upper Parking Lot. Pittsburg, CA 94565. Google Maps Link.

Hike length: This hike will be 2-3 miles long.

Hike difficulty: This is a moderate - difficult hike with roughly 800 feet of elevation change. Be prepared for uneven terrain.

Parking: Black Diamond Mines Upper Parking Lot. Pittsburg, CA 94565. Google Maps Link. Please note that there is a $5 fee to park in this parking lot.

Weather Note: Be prepared for VERY warm temperatures, so bring lots of water, sun screen, and sun protection.

Access to restrooms and water: There is a double stall vault toilet at this parking lot, and a toilet near the upper picnic area.

Other notes: Bring at least 2 liters of water, snacks, sunscreen, a wide-brimmed hat, and sun protection. Comfortable, close-toed walking shoes are recommended. No dogs are allowed on Bay Nature hikes. All minors must be accompanied by a guardian for the duration of this event. Bring hiking poles, cameras, and binoculars if preferred. Please note you may encounter ticks, poison oak, and other hazards along the way. Please note that there is a $5 fee to park in this parking lot.

Photo by © Ken-ichi Ueda, some rights reserved (CC-BY) via iNaturalist