The Michigan DNR’s page on Bright and Glory Lakes near Grayling includes maps. They say that both lakes have floating piers & boat launches for fishing – species include largemouth bass, rainbow trout, smallmouth bass, sucker, sunfish, yellow perch:
These lakes are called Kettle Lakes as they are shaped like tea kettles. They are roundish and deep in the center (more than 40 feet). The lake bottom is marl, so wading and swimming are prohibited as people would sink in the marl.
Here’s more about Kettle Lakes from MSU’s Geology department:
Kettles are depressions left behind after partially-buried ice blocks melt. Many are filled with water, and are then called “kettle lakes”. Most lakes in Michigan could be described as kettle lakes, and the term “kettle lake” describes the way the lake basin was formed. Kettle lake basins were formed as the glaciers receded. While this was happening, a block of ice broke off the glacier, and just sat there. As the glacier continued to melt, the debris from the glacier (soil, rocks, stones, gravel, etc.) filled in around the block of ice. When the block of ice finally melted, all the debris surrounding it fell into the hole, creating the kettle type basin, which when filled with water, became a lake as we know it.
Many of our small, deep lakes in Michigan are kettle lakes. Some have since been infilled with vegetation and plant matter, to form bogs. Even some of our larger, deep lakes, like Higgins Lake and Walled Lake, are kettles.