National Park Service archaeologists are sampling sediment, sucking up mud and water about 10 feet deep with an aluminum tube and then dumping the contents over a screen. When the pond was dredged in 1968 after a record drought, a park ranger noticed hundreds of artifacts, including bone pieces sharpened into tools or weapons, atop a debris pile. The items were put into plastic bags filled with yellow-brown water to keep them from drying out before they can be examined in a lab for evidence of human alteration, like cuts or drilled holes. State and federal officials consult with Florida's tribes on how to preserve artifacts or cultural sites affected by restoration projects in the park and on state lands. Tourists are warned that anything dropped into the Everglades is more than likely gone for good, but the flowing waters and annual dry seasons sometimes reveal lost treasures.