Two different theories postulate that the spit originates either from the tidal swells and currents of Cook Inlet and Kachemak Bay over millennia of sand buildup, or that it was pushed into place by now-retreated glaciers. In 1899, the Cook Inlet Coal Fields Company laid a railroad track along the spit, connecting the docks to the coal fields along Kachemak Bay. The resulting business led to the development of what eventually became Homer, Alaska. In the 1960s, several hippies, known as "spit rats", traveled from all around to camp on the Homer Spit, many of them becoming successful commercial fishermen over time. The 1964 Alaska earthquake shrank it to , and killed most of the vegetation, making it today mostly gravel and sand.