Operation Habbakuk

In 1943 A Scottish regiment of special mountain troops called the Lovat Scouts trains in winter conditions in Jasper. That same year, Operation Habbakuk, a prototype barge of sawdust and ice, is built and tested in secrecy at Patricia Lake. Military command hopes to float such barges as mid-Atlantic airfields. Although shown to be resistant to enemy attack, such ships are never deployed. The test model is abandoned in 1944 and its infrastructure sinks to the bottom of Patricia Lake.
A quote from Park’s Canada history section.

Pyramid Mountain overlooking Pyramid and Patricia Lakes

Patricia Lake and Pyramid Lake are small lake’s located on the “Pyramid Bench” in Jasper National Park, Alberta, Canada.

Patricia Lake

The Lakes lie at the foot of Pyramid Mountain, a natural landmark that overlooks the town of Jasper.

Pyramid Lake Island

Patricia and Pyramid Lake are connected by hiking trails to the town of Jasper.

Patricia Lake

No motor boats allowed

Pyramid lake