The Bayport area preserves a long record of natural and human history. During the Eocene Period, 45 million years ago, the Gulf covered this region, and local Ocala limestone deposits preserved marine shells, plants, and mammal bones, including early shark toothed whales, now-extinct sea boas, and sea turtles. By the late Oligocene Period, 30 million years ago, the shallow sea over west Florida began to recede, allowing land animals and plants to live in the area. During the Early Miocene Period, 25-10 million years ago, vast forests of conifers and deciduous trees supported giant pigs, rhinoceros, and small camels, while fossils of small rodents, carnivores, and early horses were left in sinkholes near Brooksville. In the Late Miocene Period, 10-4.5 million years ago, many species of the 3-toed horse were hunted by false saber toothed cats and bone eating dogs. During the Ice Age, 1.5 million years ago-13,000 years ago, lower sea levels pushed the Gulf's coast 70 miles west of Bayport, and mammoths, mastodons, ground sloths, and saber tooth cats roamed the coastal lowlands; their fossilized remains have been found in Weeki Wachee Springs. Around 13,000 years ago, Paleo-Indians arrived in the Bayport area when the climate was cooler and drier and the Gulf of Mexico was 200 feet lower, using large spears with stone points to hunt mammoth and mastodon. By 9,000 years ago, a warmer climate and rising seas led Archaic Period people to pursue a hunting and gathering lifestyle, using stemmed spear points and also gathering shellfish and catching fish in nets and traps. By 2,500 years ago, Deptford Culture people lived in small settlements along the Gulf, used shell tools, and relied heavily on marine resources. A Bayport burial mound excavated in the late 19th century contained artifacts dating from the Weeden Island Culture 1,100-1,700 years ago. Evidence of Safety Harbor Culture people dating from 1,000 to 450 years ago was found within a burial mound at Weeki Wachee Spring and included early Spanish Contact Period artifacts. These native people were living around Bayport during the expeditions led by Panfilo de Narvaez in 1528 and Hernando de Soto in 1539.