Five hundred million years ago, limestone was forming in ancient seas while no plants or animals were found on land. Primitive plants and animals lived in the oceans, and the molecular building blocks of Cockeysville Marble were joining together and precipitating onto the ocean floor as limy mud. Over millions of years, continents repeatedly collided, causing catastrophic geological upheavals that buried limestone formations deep within the earth. Intense heat and pressure from this ancient geologic activity recrystallized the limestone at Oregon Ridge into marble. By the late 1700s, prospectors searching the area for mineral deposits knew there was iron ore at Oregon Ridge, and the property also contained marble, a key ingredient in the iron-making process. In this quarry pit, miners blasted large chunks of marble from the rock mass, then pounded those chunks into pieces that could be loaded into carts and hauled to the furnace. Teamsters using mule-drawn tip-carts piled iron ore, coal, and marble near the furnace. Most of the mined marble was used in the furnace mix, though some was used in house foundations and as liming in the water well. The marble was mined by one worker holding and turning a star-drill while another pounded it with a heavy sledgehammer; the drilled hole was filled with black powder and a fuse, tamped, and ignited to blast loose large chunks of marble.