List of Slides for Isle Royale NP

• Isle Royale is part of the Canadian Shield, shown here in an aerial view of Labrador.
• Another view of the Canadian Shield reveals structures typical of erosion by scouring glaciers.
• An aerial view of the park shows parallel ridges and islands, valleys and lakes, developed by differential erosion on tilted rock layers with varying hardness.
• Ridges (sometimes isolated as islands) form along resistant rock layers, and valleys (sometimes containing lakes) form along easily-eroded layers.
• Access to Isle Royale is by sea plane or ferry.
• The intrepid can travel by canoe, as these paddlers are doing in rough water on the south side of the island.
• Approaching by ferry, you can see dipping volcanic flows, now eroded into sea cliffs.
• Sea cliffs (palisades) eroded along the strike of volcanic rocks form part of the north shore of the island.
• There are no roads on the island, but backpackers enjoy hiking the central High Trail along Greenstone Ridge.
• The parallel ridges and valleys visible from the air are apparent at ground level too.
• Here is a typical view, along the NE end of the south side of Isle Royale.
• In places, the Precambrian volcanic rocks have been fractured and eroded.
• In other places, such as the Rock Harbor area, the rocks have been smoothed and polished by Pleistocene glaciers.
• Contemplate the vast stretch of time between the Precambrian eruption of this pillow basalt and its Pleistocene glacial polishing!
• A closeup view of the basalt shows the marks left after the passage of the ice.
• Prehistoric people mined copper associated with these ancient lava flows on Isle Royale and the Keewenaw Peninsula of Michigan.
• A lucky backpacker may meet one of the present-day inhabitants face to face!
• Isle Royale is a popular summer destination for those who like to camp away from the crowds.
• For leanto camping, access is first come, first served.
• A beaver dam between two ridges has formed this inland lake - good fishing here!