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 Okeechobee muck. By the 1960s, all of these settlements were abandoned. In 1926 the Great Miami Hurricane hit the Lake Okeechobee area, killing approximately 300 people. Two years later in 1928, the Okeechobee Hurricane crossed over the lake, killing thousands. The Red Cross reported 1,836 deaths which the National Weather Service initially accepted, but in 2003, the number was revised to "at least 2,500". In both cases the catastrophe was caused by flooding from a storm surge when strong winds drove water over the mud dike that circled the lake at the time. After the two hurricanes, the Florida State Legislature