Representative of the type of technology developed in the late 19th century and early 20th century to provide large, inexpensive supplies of crushed stone for the vast American railroad network and later for the road construction, it is believed to be the largest intact steam shovel remaining in the world,[2] and may have been used in the excavation of the Panama Canal.

The shovel is located on the north side of Gulf Road, two miles (3.2 km) east-northeast of the village of Le Roy, just opposite the driveway into the Hanson Company's limestone quarry.

The Register listing includes an area of about 0.1 acres (0.04 ha), delineated by a perimeter 10 feet (3.05 m) around the shovel.

The operator's cab is on the east-facing front end, with most of the rest of the section housing the shovel's three steam engines and a 5-by-15-foot (1.52 by 4.57 m) boiler, no longer in working condition, with horizontal flues.

Le Roy, near the Onondaga Escarpment, was a prime location for limestone quarrying, atop a 150-foot (45.72 m) layer of the stone.

It began to pioneer the new field of manufacturing aggregate, particularly a patented blend called Amiesite, for road surfaces.

[4] On March 14, 1906 the local newspaper at the time, the Le Roy Gazette, reported on the new equipment that began operation that day.

Sixteen were purchased by the commission and used to dig the canal; one of them set what was then a world record in 1912 when it dug 5,554 cubic yards (4,246 m3) of earth from a pit at the site of Gatun Dam.

The operator sat in the front booth and used levers to move the hoist and lift and lower the bucket.

A cranesman, who sat on the left-hand side of the boom, controlled the crowd engine, which allowed him to set the depth of the cut and release the bucket's contents when it was full by tugging on a wire rope attached to it.

They also set up the jackscrews necessary to stabilize the shovel in front of the rock face it was digging and dismantled them when it was time to move.

[4] The Model 91 continued in use at the Le Roy quarry through the 1930s, gradually being displaced by newer diesel-powered equipment.

At some point before World War II its original wood siding was replaced with the current metal.

The quarry across the road has remained in operation, now under the ownership of Dolomite (CRH Americas Materials) who donated the stone for the pull-off area to view the shovel.