Heavy hauling had to take place during a two-month period in late winter when the lake ice was thick enough.

Their water flow covered the lake ice.

This lake has a 93.4 m (306 ft) deep water column that lies sealed beneath a 3.6 to 4.0 m (12 to 13 ft) thick perennial lake ice.

Glaciers form only on land and are distinct from the much thinner sea ice and lake ice that form on the surface of bodies of water.

It closes when the lake ices over and reopens when it thaws.