The Ontario, or Ontario Shaft, coal mine was started circa 1920 by Ontario Gas Coal Company. In later years it was a mine of Buckeye Coal Co., which was a coal mining subsidiary of Youngstown Sheet and Tube. Sheet and Tube also operated the large and long-lived Nemacolin mine in neighboring Greene County.

Mar. 2018 image by author

An old building left over from the coal mine with the coal company housing in the background.

Mar. 2018 image by author

End view of the same abandoned coal mine shop building. There was also another structure next to it enveloped in weeds.

Mar. 2018 image by author

The Ontario, Pa. patch town. This is located over the hill from the large Cokeburg patch town.

Mar. 2018 image by author

Some of the coal company houses are of wood-framed construction, but some are brick.

Mar. 2018 image by author

Closer view of an uninhabited brick patch house which, except for the concrete steps, appears to be unaltered since it was first constructed.

Mar. 2018 image by author

These slightly more substantial homes were probably for mine foremen and other management.

From a Connellsville Weekly Courier article from June 3, 1920 titled, "Six Men are Killed in Blast in Shaft in Washington County:"

"At least six men were killed by an explosion in the coal shaft of the Ontario Gas Coal Company near Cokeburg, Washington County, Pa. The men were buried under tons of earth and the foreman in charge of the work said he would not be able to tell the exact number of dead until the bodies had been recovered. The men were employed by the recently formed Ontario Gas Coal Company in sinking a shaft for coal and had reached the top of the coal late yesterday. Soon after they went down the shaft today to resume work there was an explosion which dislodged a great mass of earth and buried every man in the shaft. The explosion was heard throughout the entire section and miners employed in other mines hastened to the spot. Life saving apparatus of the Bureau of Mines was brought into use but was of no avail. Forces of volunteer workers were quickly organized to dig out the buried men. First reports in the Pittsburg stations of the Bureau of Mines were vague as the shaft is some distance from telephones and reports sent out by nearby mining villages were that 30 or 40 men had been killed. Officers of the station left here this afternoon for the scene of the accident."