Places We Protect

Yellow Island Preserve


(ALL INTERNAL RIGHTS) The Nature Conservancy members of Washington State head to Yellow Island in the San Juan Islands. Photo credit: © Cameron Karsten
WOPA160126_D170 (ALL INTERNAL RIGHTS) The Nature Conservancy members of Washington State head to Yellow Island in the San Juan Islands. Photo credit: © Cameron Karsten © © Cameron Karsten

Gem of the San Juan Islands; this preserve is known for its dramatic wildflower displays.



Why You Should Visit

Yellow Island is among the most colorful of The Nature Conservancy's preserves, long known to passengers aboard Washington's San Juan Islands ferries for its dramatic wildflower displays. The small island’s springtime floral display is greater than that of any similar-sized area in the 170-island San Juan archipelago.

Why TNC Selected this Site

The grasslands on Yellow Island are unique in the Puget Sound lowlands. An absence of historic grazing helped preserve the unusual diversity of native plants. This also prevented them from being overrun by non-native species. The opportunity to purchase the entire island in 1979 allowed TNC to protect this fragile system.

What TNC is Doing

TNC has carried out an extensive ecological research program on Yellow Island since 1980. Ongoing studies have focused on understanding the extent and rate of invasion of the grasslands by woody species, controlling and reversing this encroachment, and developing strategies for restoring native species where they have been locally eliminated. The results have been shared with partner organizations and agencies to help maintain and restore grasslands throughout the Puget Sound lowlands.

This work is being done by TNC ecologists, land stewards (who live on Yellow Island year-round), and numerous volunteers. These efforts have been supported by generous donations from visitors, TNC members, and the U.S. Fish and Wildlife Service.



Groups of more than six people require written permission.


Open year-round, between 10 a.m. to 4 p.m. 


11 acres

Explore our work in this region

What to See: Plants

More than 50 species of wildflowers, including broadleafed shooting star, hairy Indian paintbrush, chocolate lily, camas and stonecrop bloom on Yellow Island. Brittle prickly pear cactus – the only cactus species native to western Washington – is also found here. Many of these plants occur throughout the San Juans, but only Yellow Island, with its open fescue meadows and the absence of resident grazing animals, hosts such dense and diverse populations.

What to See: Animals

Bald eagles frequently perch in the island's tallest trees. Harbor seals haul out on the rocks off the island's west spit while using the east spit to give birth and nurse their young. Harlequin ducks forage near shore, taking advantage of the prolific life in the intertidal zone. The black oystercatcher's chisel-shaped bill is well suited for prying limpet, chiton and other shellfish from the rocks at low tide. Hummingbirds and several species of songbirds nest on the island. Mink and river otters are the only mammals commonly seen on the island.

Farther from the island's wave-swept, weather-beaten coast, orca whales travel in large family groups called pods. Other marine mammals – minke whales, harbor porpoises, and California and Steller’s sealions – swim in the nutrient-laden currents that bathe Yellow Island.

Please land and come ashore only at the southeast beach, below the wooden Dodd cabin. The east spit is open to landings only in the spring and fall; watch for local signage. Do not beach small boats or kayaks on the west spit. No camping or overnight mooring is allowed.

When visiting this preserve, please stay on the established trails. Groups of more than six people require written permission before visiting Yellow Island. To arrange for such a visit, please contact TNC at 206-343-4344.

No pets allowed on the preserve.