Eagle Lake - Freshwater Coral

[ballfrog]

It's not actually coral.  Instead it is a type of algae that grows on the rocks.  Sometimes they are referred to as stromatalytes.

It does make the rocks look somewhat like coral heads, but there are no polyps. 

I have found the same types of growth in a couple other lakes, including Pebble in Fergus Falls.

One place that I found a ridge was straight out from the boat landing at the park at about 34 feet deep.  It's a long swim though, so the boat and sonar idea is a good one.