The Casual Hiker
@sfhiker.bsky.social
SF-based computational biologist, hiker, nerd. All things history/prehistory, science, tech, nature, and sustainability. Also SF and California politics.
A river otter chomping on a fish at Phoenix Lake today.
October 13, 2025 at 3:30 AM
A river otter chomping on a fish at Phoenix Lake today.
Juvenile bobcat encounter on Tennessee Valley Trail.
September 14, 2025 at 4:23 AM
Juvenile bobcat encounter on Tennessee Valley Trail.
Ring Mountain is lovely. It's a great place to hike in any season. Would be a good to bring along a geologist. 8/end
May 19, 2025 at 1:37 AM
Ring Mountain is lovely. It's a great place to hike in any season. Would be a good to bring along a geologist. 8/end
There are other rare species here, for example Oakland Star Tulip. 7/n
May 19, 2025 at 1:37 AM
There are other rare species here, for example Oakland Star Tulip. 7/n
Luckily, I was able to find a better looking one. Doug mentioned that the TLM only grows here because of the unusual geology of the mountain. I guess the plant adapted to the high magnesium content in the serpentine soil and it can't spread elsewhere. 5/n
May 19, 2025 at 1:37 AM
Luckily, I was able to find a better looking one. Doug mentioned that the TLM only grows here because of the unusual geology of the mountain. I guess the plant adapted to the high magnesium content in the serpentine soil and it can't spread elsewhere. 5/n
They showed me a TML specimen. I was a few weeks too early, though. The flower hadn't bloomed yet -- the plant looked a stalk of grass. But they also pointed me to a trail where there are more of them. 4/n
May 19, 2025 at 1:37 AM
They showed me a TML specimen. I was a few weeks too early, though. The flower hadn't bloomed yet -- the plant looked a stalk of grass. But they also pointed me to a trail where there are more of them. 4/n
Tiburon Mariposa Lili (TML) blooms only for a few weeks a year, starting late May. There were a many wildflowers on the trail, but no TLMs. I was disappointed. Then I came across two Marin Parks volunteers: Doug and Belle. 3/n
May 19, 2025 at 1:37 AM
Tiburon Mariposa Lili (TML) blooms only for a few weeks a year, starting late May. There were a many wildflowers on the trail, but no TLMs. I was disappointed. Then I came across two Marin Parks volunteers: Doug and Belle. 3/n
This area is interesting geologically as well as archaeologically. There are large boulders scattered around here some displaying petroglyphs carved by the Miwoks. I wasn't able to spot any though. I need to come back for it. 2/n
www.megalithic.co.uk/article.php?...
www.megalithic.co.uk/article.php?...
May 19, 2025 at 1:37 AM
This area is interesting geologically as well as archaeologically. There are large boulders scattered around here some displaying petroglyphs carved by the Miwoks. I wasn't able to spot any though. I need to come back for it. 2/n
www.megalithic.co.uk/article.php?...
www.megalithic.co.uk/article.php?...
Having missed last week's $10K treasure hunt, I decided to hunt for another treasure myself this weekend: the Tiburon Mariposa Lily, which grows only in Tiburon and nowhere else in the world. ONLY in the Ring Mountain Preserve in Tiburon. So I headed there yesterday to try my luck. 1/n
May 19, 2025 at 1:37 AM
Having missed last week's $10K treasure hunt, I decided to hunt for another treasure myself this weekend: the Tiburon Mariposa Lily, which grows only in Tiburon and nowhere else in the world. ONLY in the Ring Mountain Preserve in Tiburon. So I headed there yesterday to try my luck. 1/n
The Methuselah tree. A majestic redwood, estimated nearly 1900 years old. Its diameter at base is about 4.25m. [Near El Corte de Madera Creek Preserve]
May 10, 2025 at 7:39 PM
The Methuselah tree. A majestic redwood, estimated nearly 1900 years old. Its diameter at base is about 4.25m. [Near El Corte de Madera Creek Preserve]
What to do when you encounter a mountain lion?
May 10, 2025 at 7:30 PM
What to do when you encounter a mountain lion?
"Lobaria pulmonaria is a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium—a symbiosis involving members of three kingdoms of organisms." [Wikipedia] 5/end
May 10, 2025 at 7:30 PM
"Lobaria pulmonaria is a large epiphytic lichen consisting of an ascomycete fungus and a green algal partner living together in a symbiotic relationship with a cyanobacterium—a symbiosis involving members of three kingdoms of organisms." [Wikipedia] 5/end
Resolution Trail, El Corte de Madera Preserve: the trail was named after an Australian Douglas DC9 that crashed here in 1953. Some debris still can be seen along the trail. 1/n
May 10, 2025 at 7:30 PM
Resolution Trail, El Corte de Madera Preserve: the trail was named after an Australian Douglas DC9 that crashed here in 1953. Some debris still can be seen along the trail. 1/n
Was this event really the beginning of the Internet Age? A commemorative plate from Alpine Inn, a beer garden near Palo Alto.
May 10, 2025 at 7:09 PM
Was this event really the beginning of the Internet Age? A commemorative plate from Alpine Inn, a beer garden near Palo Alto.
The Rangehouse: the old US Naval Magnetic Silencing Range in the Marina. The facility was used to calibrate naval vessels' magnetic signatures to avoid detection by mines etc.
May 10, 2025 at 7:02 PM
The Rangehouse: the old US Naval Magnetic Silencing Range in the Marina. The facility was used to calibrate naval vessels' magnetic signatures to avoid detection by mines etc.
East Bay in the distance.
April 13, 2025 at 4:13 PM
East Bay in the distance.
Flowers: seep monkey flower, coastal tidytips, poppies, hairy vetch, pacific false bindweed.
April 13, 2025 at 4:13 PM
Flowers: seep monkey flower, coastal tidytips, poppies, hairy vetch, pacific false bindweed.
The preserve is in Tiburon. It's named after the church that was built in 1888. Never seen such a bell tower before. The small building next to it is the outhouse.
April 13, 2025 at 4:13 PM
The preserve is in Tiburon. It's named after the church that was built in 1888. Never seen such a bell tower before. The small building next to it is the outhouse.
After 15 years of hiking in the Bay, I still find new and amazing trails. The weather was perfect for Old St Hillary's Wildflower Preserve yesterday. Made me feel truly blessed to live in the Bay. 🧵
April 13, 2025 at 4:13 PM
After 15 years of hiking in the Bay, I still find new and amazing trails. The weather was perfect for Old St Hillary's Wildflower Preserve yesterday. Made me feel truly blessed to live in the Bay. 🧵