It is endemic to Marin County, California, where it is known only from one population on Ring Mountain east of Mill Valley.

[2][3] Calochortus tiburonensis is a perennial growing from a bulb to 10–60 cm in height with a single leaf.

When mature, ovaries form a capsule full of small, dark brown seeds.

[8] It is protected along with a number of other rare serpentine soils endemic plants that grow on and around Ring Mountain.

[6][1] While the land is protected, the flora upon it are still vulnerable to events such as wildfires or drought, and to damage from off-leash dogs, hikers, cyclists, vandals, and wildflower collectors.