The Greenstone Ridge Trail is the 40 miles (64.4 km)-long primary hiking

Hiking

Hiking is an outdoor activity which consists of walking in natural environments, often in mountainous or other scenic terrain. People often hike on hiking trails. It is such a popular activity that there are numerous hiking organizations worldwide. The health benefits of different types of hiking...

 trail that serves Isle Royale National Park

Isle Royale National Park

Isle Royale National Park is a U.S. National Park in the state of Michigan. Isle Royale, the largest island in Lake Superior, is over 45 miles in length and 9 miles wide at its widest point. The park is made of Isle Royale itself and approximately 400 smaller islands, along with any submerged...

. It extends from the a harbor on Isle Royale

Isle Royale

Isle Royale is an island of the Great Lakes, located in the northwest of Lake Superior, and part of the state of Michigan. The island and the 450 surrounding smaller islands and waters make up Isle Royale National Park....

's western end, Windigo

Windigo Ranger Station

Windigo Ranger Station, or simply Windigo, is a docking and refueling port on Isle Royale, the largest island in Lake Superior, and is a ranger station for Isle Royale National Park. Along with Rock Harbor, it is one of only two ports for visitors to enter the national park...

, to a harbor and lodge on its eastern end, Rock Harbor

Rock Harbor

Rock Harbor is the main access point for visitors landing on Isle Royale in northern Lake Superior. It sits at the northeastern end of the forty-five mile long island, the whole of which is protected as Isle Royale National Park...

. As there are no paved roads in this wilderness area

Wilderness

Wilderness or wildland is a natural environment on Earth that has not been significantly modified by human activity. It may also be defined as: "The most intact, undisturbed wild natural areas left on our planet—those last truly wild places that humans do not control and have not developed with...

 and park, the trail doubles as the primary means of land transportation on the island.

The trail generally follows the top of Greenstone Ridge, a low ridge

Ridge

A ridge is a geological feature consisting of a chain of mountains or hills that form a continuous elevated crest for some distance. Ridges are usually termed hills or mountains as well, depending on size. There are several main types of ridges:...

 that forms the spine of the island, and surmounts Mount Desor

Mount Desor

Mount Desor is the tallest mountain within Isle Royale National Park. Located on Isle Royale in Lake Superior and with an elevation of , it is the third highest peak on the lake....

, the highest point of Isle Royale. Hikers appreciate the elevation, which to some extent separates them from assaults by mosquitoes that are found in great numbers in the island's lower-lying wetland

Wetland

A wetland is an area of land whose soil is saturated with water either permanently or seasonally. Wetlands are categorised by their characteristic vegetation, which is adapted to these unique soil conditions....

s. Hikers often look out for signs of the island's megafauna

Wolves and moose on Isle Royale

Isle Royale, the principal island of Isle Royale National Park in the United States, is home to a predator-prey relationship between wolves and moose that is unlike any other in the world...

, moose

Moose

The moose or Eurasian elk is the largest extant species in the deer family. Moose are distinguished by the palmate antlers of the males; other members of the family have antlers with a dendritic configuration...

 and wolves; although scarce and shy, these animals live all about the scrubby woodlands that adjoin the trail.

The Greenstone Ridge and its Trail are both named after chlorastrolite

Chlorastrolite

Chlorastrolite also known as Michigan Greenstone, is a green or bluish green stone. Chlorastrolite has finely radiated or stellate masses that have a "turtleback" pattern. The stellate masses tend to be chatoyant, meaning they have a changeable luster. This chatoyancy can be subtranslucent to...

, a local semiprecious stone that is the state gem of the U.S. state of Michigan

Michigan

Michigan is a U.S. state located in the Great Lakes Region of the United States of America. The name Michigan is the French form of the Ojibwa word mishigamaa, meaning "large water" or "large lake"....

. On Isle Royale this rock is known as "greenstone."