In the eastern lap of the Singatse Mountains, a remnant remains from bygone days.

Bluestone Mine, on an uphill spur West of Mason, had its own horsepower to pull the hill. If the Baldwin 2-8-0's on the NCB line were the 'oxen,' then Bluestone's 37 ton Heisler was the 'bulldog' of rails. This is the original loco, but it can't be found at the Bluestone Mine, nor in Mason any more. After some migration, it wound up at Willits California in the Roots of Motive Power museum. On selected occasions, volunteer engineers pull it out, and carry happy passengers in a circle.