Its habitat includes a large portion of the coastal areas of the northern hemisphere, mainly polar regions, and it lives a solitary life for up to 80 years.

The tentacles, superior of the column and usually 100 in number, are green to opaque cream with red and white striations and semi-transparent when extended.

In the northeastern Pacific Ocean, it ranges from intertidal and subtidal zones of the Pribilof Islands, Alaska to Monterey, California.

In the state of Washington this sea anemone more commonly frequents the Puget Sound compared to the Pacific Ocean front.

It is found in a lower intertidal, upper subtidal zone - 30 m deep, inhabiting well protected and shaded areas.

This sea anemone is frequently found on docks, wood pilings, and under large rock outcroppings.

Urticina crassicornis senses predation through a simple nerve net spanning along its column and tentacle walls.

Spawning occurs in the spring amongst Puget Sound populations, when eggs (yolky, 0.7 mm in diameter) and sperm are released into the sea for fertilization.