There may also be features underwater in the adjacent black mangrove forest, dating to when the sea level was lower.

Oyster, clam, conch and lightning whelk shells are also found in the middens.

The shell works and middens are attributed to the Caloosahatchee culture IIA-IV period, about 500–1500.

In 1992, the NRHP Registration Sheet described the Mark Pardo Shellworks as "one of the best preserved archaeological sites in the region."

This article about a property in Lee County, Florida on the National Register of Historic Places is a stub.