[JSDude1]

Hmmm didn’t know two things: #1 that coral reefs were possible in lake Michigan, and #2 that there were pirates in Lake Michigan.

[Cold Heart]

Article said reefs, no mention of coral.

The reefs were four feet deep, the trailerable boat I’m building is going to have a three foot draft. I’m headed that way some day:)

[meadsjn]

There were pirates up and down the Mississippi who preyed mostly on the riverboats.

I read a fiction book in grade school set on the Mississippi, about a gunsmith who was working to develop and improve breech-loading firearms to help repel the pirates.

[marktwain]

Reefs do not have to be coral.

[A Formerly Proud Canadian]

There were also pirates on the Saskatchewan!

The Last Saskatchewan Pirate

[Slyfox]

The only coral that you would ever find in the Great Lakes area would be incased in rock and broken into stones as a result of the movements of the glaciers which formed the Lakes.

[Boogieman]

The article said reefs, not coral reefs. Coral can't grow in freshwater, but freshwater reefs can be formed by other means, such as tufa deposits.

[Jabba the Nutt]

Michigan designated the Petoskey stone as the official "state stone" in 1965 (Petoskey stone is actually not a stone but fossilized coral). In prehistoric times (about 350 million years ago), Michigan was covered by a shallow sea that teemed with coral colonies. These beautiful fossils are what remains.

[grellis]

Coral reefs don’t exist in the Great Lakes now (my inner dork is about to bust through) but Michigan was at one time covered by an inland ocean. The Petoskey Stone, our state fossil, was coral.

[Elsie]

It didn’t say ‘coral’.

[Dr. Bogus Pachysandra]

Petosky stones. I have found several in Glen Lake, separated from Lake Michigan by The Sleeping Bear Sand Dunes. A wonderful, wonderful place!
“A Petoskey stone is a rock and a fossil, often pebble-shaped, that is composed of a fossilized rugose coral, Hexagonaria percarinata.[1] The stones were formed as a result of glaciation, in which sheets of ice plucked stones from the bedrock, grinding off their rough edges and depositing them in the northwestern (and some in the northeastern) portion of Michigan’s lower peninsula. In those same areas of Michigan, complete fossilized coral colony heads can be found in the source rocks for the Petoskey stones.

Petoskey stones are found in the Gravel Point Formation of the Traverse Group. They are fragments of a coral reef that was originally deposited during the Devonian period.[1] When dry, the stone resembles ordinary limestone but when wet or polished using lapidary techniques, the distinctive mottled pattern of the six-sided coral fossils emerges. It is sometimes made into decorative objects. Other forms of fossilized coral are also found in the same location.”

[Hot Tabasco]

An extensive reef system about four feet under the water

More likely shallow sand bars which inhabit the great lakes as well as attached lakes such as lake Charlevoix.......

[Dr. Bogus Pachysandra]

“Hmmm didn’t know two things: #1 that coral reefs were possible in lake Michigan, “