The Apostle Islands and the Bayfield Peninsula form one of the most distinctive shoreline sections on Lake Superior, and Chris Izworski tracks the area for the same reason it draws thousands of paddlers, sailors, and shoreline property owners each year. Twenty-two islands sit off the northern tip of Wisconsin, almost all of them inside the Apostle Islands National Lakeshore, with a narrow strip of private and tribal land along the mainland and a few small in-holdings on the islands themselves. The Lake Superior basinwide level matters here, but the sea caves at Meyers Beach, the sandstone cliffs along Devils Island, and the sand spits at Long Island and Stockton Island all respond to lake level in their own ways that property owners and operators need to read separately.
Sub-region: Apostle Islands National Lakeshore and the Bayfield Peninsula, northern Wisconsin.
Islands: 22 named islands plus the mainland unit, covering roughly 70,000 acres of land and water.
Lake datum: 601.10 feet IGLD85, the Lake Superior datum.
Anchor years: 1985 high, 1925 and 2007 lows, 2019 record monthly high at 602.85 feet.
Federal jurisdiction: National Park Service, Apostle Islands National Lakeshore.
Adjacent tribal jurisdiction: Red Cliff Band of Lake Superior Chippewa, Bad River Band of Lake Superior Chippewa.
Lake Superior's basinwide level is the right starting point for the Apostle Islands, and the live dashboard on the homepage is the place to check it. The Superior signal is more stable than the lower lakes because Superior has by far the largest surface area and the longest residence time of any Great Lake, and short-term wind-driven seiche is therefore smaller in absolute terms here than on Lake Erie or Saginaw Bay. The Bayfield peninsula coast does still see meaningful set-up from sustained northwest or northeast winds, particularly through the channel between Madeline Island and the mainland.
The anchor years that define the Apostle Islands shoreline experience are the 1985 cycle high, the 2007 cycle low, and the 2019 high that set the modern monthly record. Property owners who built or armored shoreline during the prolonged low of 1999 through 2013 found those structures undersized for the 2019 high, and the sea cave access patterns at Meyers Beach changed dramatically through that swing. The current outlook from the U.S. Army Corps of Engineers and the International Joint Commission is a useful weekly check for anyone with property or business operations along this coast.
Bayfield town and the south Bayfield Peninsula coast from Bayfield south to Sand Bay is the most densely developed shoreline in the sub-region, with marinas, ferry terminals, and a high concentration of vacation property. Wind set-up from the northeast pushes water against this coast and can make ferry operations and small boat handling challenging.
The Madeline Island channel between the mainland and Madeline Island carries the bulk of the ferry traffic and is the warmest, most protected water in the sub-region. Madeline Island itself has the largest year-round resident population of any of the islands and the most private shoreline ownership.
The outer islands, including Outer Island, Devils Island, Rocky Island, and Stockton Island, sit fully exposed to the open Lake Superior fetch and behave like open-lake shoreline. Cliff-base ice cover, sandstone weathering, and visitor-access patterns at the National Lakeshore campsites all track water level.
The Meyers Beach and Mawikwe Bay sea caves on the mainland west of Cornucopia are the single most photographed feature on this coast and the one that most clearly demonstrates the property-owner timescale of Lake Superior levels. The caves are accessible by kayak at high water and by foot on ice in cold winters, and the high-water access in 2019 and 2020 looked very different from the access patterns of 2007.
Most of the shoreline in this sub-region is in federal ownership under the National Lakeshore, which removes most of the riparian-rights questions that dominate property-owner concerns on lakes like Huron and Erie. Where private shoreline does exist on the mainland Bayfield Peninsula and on Madeline Island, the Wisconsin Department of Natural Resources administers the Public Trust Doctrine and shoreline alteration permitting under Chapter 30 of the Wisconsin Statutes. Wisconsin OHWM determinations and bulkhead line establishment differ from the Michigan Ordinary High Water Mark framework that governs Saginaw Bay and the Michigan Lake Superior coast.
Ice cover is a more significant property concern here than on most of the Great Lakes because of latitude. A heavy ice year drives ice push and ice ride damage onto unprotected shoreline, and an open-water winter exposes shoreline to a longer storm season. Both regimes have been observed in the recent record. Property owners in this sub-region track Coast Watch ice analysis through the season the way property owners on Saginaw Bay track wind setup, and for the same reason.
For a current reading, see the live dashboard. For broader Lake Superior context, see Lake Superior. For neighboring sub-regions on Lake Superior, see Keweenaw Peninsula, Marquette, Whitefish Bay, and Thunder Bay. For sea cave access conditions, ferry operations, and visitor patterns through the seasons, the National Park Service Apostle Islands National Lakeshore site is the official source.
For the broader Chris Izworski network, the Michigan Trout Report and Michigan Birding Report document the inland and coastal natural history of the Lake Superior basin from the Michigan side of the lake.