Lake Okeechobee Valley and the Everglades. The trough is underlain by clay deposits that compacted more than the limestone and sand deposits did along both coasts of peninsular Florida. Until about 6,000 years ago, the trough was dry land. As the sea level rose, the water table in Florida also rose and rainfall increased. From 6,000 to 4,000 years ago, wetlands formed building up peat deposits. Eventually the water flow into the area created a lake, drowning the wetlands. Along what is now the southern edge of the lake, the wetlands built up the layers of peat rapidly enough (reaching thick) to
Lake George (Florida) second largest lake in Florida, after Lake Okeechobee. Lake George was the third largest lake behind Lake Apopka, but conversion of the littoral zone on the northern side of Lake Apopka to farm fields in the previous century reduced its surface area. The name of Lake Welaka is taken from "Welaka" (meaning "chain of lakes"), the name for the St. Johns River in the language of the Timucua, who inhabited the region prior to European settlement. The first European to visit the lake was Pedro Menéndez de Avilés, who as the Spanish governor of Florida, explored the St. Johns River