Massive steel iron ore docks protrude into Agate Bay, replacing earlier smaller wooden docks built between 1883 and 1896. Of the three steel docks, only Dock 1 and Dock 2 remain in service. Dock 1, the closer dock, was built in 1911, stands 75 feet above the waterline, and is 1,344 feet long. Dock 2, the newest and largest steel dock, was built in 1916, is 80 feet high, and 1,368 feet long. Taconite pellets from mines in Northern Minnesota arrive by railroad cars and are dumped into pockets on both sides of the docks, or into the yard and then brought to Dock 2 by conveyor. Ore boats 1,000 feet long moor alongside under the pockets and are loaded in about 7 hours, each carrying 55,000 to 60,000 tons of taconite pellets, about the amount that fills 800 railroad ore cars.