Steep Rock Lake is a body of water near the township of Atikokan, northern Ontario, Canada.

[2] Active speculation about mining the area began as early as 1885, when land deposits were bought by the McKellar and Graham families.

[1] Julian Cross, a mining prospector, later came to the area in 1926 and in 1937 through exploratory drilling located a major orebody under Steep Rock Lake.

This specimen may have been deposited here by a barren-ground caribou at the end of the last ice age, demonstrating that the species once lived in this region.

Morlock founded the Steerola Expedition Company Limited to finance a drilling project on Steep Rock Lake led by Julian Cross.

In March of the same year, Cross discovered a body of iron ore under Steep Rock Lake after 6 test holes were drilled.

The Steerola Expedition Company did not have the necessary funds to develop a mine, so Steep Rock Iron Mines Limited was created February 24, 1939 with Joseph Errington as president and managing director, Julian Cross as vice-president and Watkin Samuel as Consulting Engineer.

In the early days of mining Steep Rock Lake, plans were made to sink a small shaft 1,400 ft. below the lake level and drill into the orebody to test the quality of the ore. July 1939 saw the collaring of the No.1 shaft with Morson Scarth (Pop) Fotheringham, then a mining engineer, in charge.

[15] At this time a new plan was already being looked into by the engineers of Steep Rock Iron Mines to drain the lake by diverting the Seine River.

The report, presented in March 1941 gave Joseph Errington and Donald Hogarth the necessary basis to approach American Financiers for the money needed to move the plan forward.

As negotiations continued into early 1942, Joseph Errington died of a heart attack on the way to a presentation in New York.

In March 1941, negotiations with the Ontario Government for the rights to dam off Steep Rock Lake were underway.

The negotiations involved Steep Rock Iron Mines Limited, Ontario Hydro and Ontario-Minnesota Pulp and Paper Company.

Patrick Harrison and his crew were hired to dig the tunnel that would lower the water level of Finlayson Lake.

Through the fall of 1943, three dams were constructed and the first pumps were put into action in the middle arm of Steep Rock Lake to dewater that section.

More than a million cubic yards of rock had to be removed to create the canal between Raft Lake and Finlayson.

It was loaded onto ships at Fort Frances and travelled to Duluth, Minnesota as the ore docks at Port Arthur were not completed by this point.

This shipment represented the first time that iron ore mined in Northwestern Ontario crossed the international boarder creating a new trade economy.

The underground mine continued operations until 1973 when it was shut down due to low productivity, high ore costs and grade control problems.

Out of necessity, Steep Rock, gradually acquired new equipment, including more shovels and trucks, until they had the production capacity to meet the tonnage requirements.

In June 1950, Donald Hogarth died and Morson Scarth "Pop" Fotheringham took over as president of Steep Rock Iron Mines.

In addition to the equipment, many of the advances in slope stability and open pit design that were widely used in Canadian mining were developed at Steep Rock.

The terms of the lease included Royalties of 95 cents per ton, and the minimum tonnage was set at 3% of the proven reserves.

Inland began an exploratory drilling program at the "C" ore body and in June 1951, it was apparent that there was no more than 27 million ton available.

[24] In 1977, Caland moved into termination planning and developed a shutdown strategy based on involvement and participation.

[29] By December 1960, Canadian Charleson Limited became a wholly owned subsidiary of Oglebay Norton Company.

During the seven years of operation the total amount of iron ore shipped from Canadian Charleson Limited was 672,895 tons.

Cliffs along the northern shoreline of Steep Rock Lake expose 2.8 Ga (Mesoarchean) stromatolite reefs.

They consist largely of giant domal stromatolites that are part of the 500 m (1,600 ft) thick Mosher Carbonate.

The level of preservation of the giant domal stromatolites and associated carbonate platform makes these cliffs a very rare, if not unique, locality to study Mesoarchean paleoenvironments and chemostratigraphy.