So What Exactly is Marl?

After World War II, the United States was involved in a large construction project and the demand for cement and lime was very high. The Lehigh Cement Company bought up the land containing First Lake, Mud Lake, and Long Lakes of the Bertram Chain because they contained large amounts of “marl”. Technically, “marl” is a result of glaciations when lime (or calcium bicarbonate) leaches through the sandy soil of the area and dissolves into the ground water. During spring runoff, the water flows into the lakes and changes into insoluble mono carbonate which is precipitated to the lake bottom. After thousands of years these deposits have reached depths of 15 – 20 feet. Marl is very useful for agricultural lime and as a source for the manufacture of Portland cement.

The Lehigh Cement Plant was located at the north edge of Mud Lake and it was there for two specific reasons; 1.) It had access to County Road 39 and, 2.) the new dam on Otter Creek below Bertram could control the water levels of Long, Mud and First Lakes, thereby making the marl more accessible with lower water levels.

Because of the marl the water remains very clear and free of water “algae blooms” in the summer while inhibiting the growth of troublesome plants and limiting the production of organic matter.