Susie Island is the largest of 13 small, rocky islands jutting out of Lake Superior amid the high cliffs and hills of the Pigeon River outlet. In geological terms, the islands are both young and old. The bedrock is slightly metamorphosed sedimentary rock, deposited in a sea over one billion years ago. These rocks were later intruded by molten magma to form resistant dikes. Glaciers of the Great Ice Age scoured the rocks many times over the last two million years, but the Susie Islands only emerged about 5,000 years ago.
In this isolation, a pioneering community of plants continues to thrive. Species that disappeared from the rest of Minnesota after the glaciers receded northward still survive here. Today, many of these plants are more typically found in Arctic and sub-Arctic regions.
Lake Superior, just off Minnesota's north shore near Grand Portage
Why the Conservancy Selected This Site
The archipelago that includes Susie island is identified in The Conservancy’s Great Lakes ecoregional plan and included in the Pigeon River conservation site.
Several factors sustain Susie Island's unique plant community. Located one-half mile from shore, the island experiences more extreme weather than the mainland, resulting in cooler, wetter conditions. Forest fires, a common occurrence on the mainland, have rarely taken hold on Susie Island. In addition, the island's sheer cliffs, rocky promontories and poor soils prove too inhospitable for many plants. This "cloud forest" environment supports a rich variety of mosses and lichens, and a blanket bog of sphagnum mosses one to three feet thick has spread over much of the island.
What the Conservancy Has Done/Is Doing
The Nature Conservancy purchased the South portion of Susie Island in 1971. The remaining section was purchased in the late 1980's. The preserve is named for Francis Lee Jaques, the Minnesota wildlife artist and conservationist. The other 12 islands are owned by the Grand Portage Band of the Ojibway Tribe. The Band and the Conservancy are working cooperatively to protect this archipelago's unique plant life. Collaborative management planning for the Pigeon River Landscape, including the Susie Islands, is underway with several partners including the Ontario Ministry of Natural Resources, the Grand Portage Band of Ojibway, and the National Park Service. Other Conservancy ownership in the area includes the Pigeon River Cliffs Preserve.
What to See: Plants
Susie Island is home to some of Minnesota's rarest plants, including alpine bistort and slender hairgrass, both species of special concern, as well as mountain or rock cranberry and common bearberry.
Other diverse plant species include Norwegian witlow grass (a state endangered species) and northern eyebright (a species of special concern), as well as pearlwort, Arctic lupine, purple crowberry, and sphagnum moss. The interior of Susie Island is carpeted with a thick layer of moss. This is a fragile treasure that is easily destroyed by walking through the forest.
What to See: Animals
Birds are abundant on Susie Island. Herring gull rookeries cover the outer rocks. American redstarts, Swainson's thrush, golden-crowned kinglets, boreal chickadees, gray jays, and several warbler species nest in the inland trees. Occasionally, the preserve is visited by moose from the mainland
Special permission from the Minnesota Chapter is required to land on Susie Island, but since most of the island's rare plants and wildlife can be viewed from the water, visitors may boat near the island without acquiring permission in advance. Boaters and kayakers are urged to beware of submerged reefs and boulders near the islands. It's most important to watch the weather carefully as sudden storms are common on Lake Superior. Permission to land on the nearby islands is required from the Grand Portage Trust Lands Department and you are encouraged to check in with the Department prior to your visit. A good view of the islands from the mainland can be found along Highway 61 between Mt. Rose and the US/Canadian customs station. While you're in the area, you may want to visit Grand Portage National Monument, and the spectacular Pigeon River waterfalls (also known as the "high falls"), in Grand Portage State Park.
Nearest services are in Grand Portage, Voyageur Marina (nearest boat landing) and US/Canadian customs.
See "Plan Your Visit" (above).