1.Salvage archaeology

2.Amazing Indian mounds

3.Effigy mound culture

4.Three Gorgeous Gorges

The Aswan High Dam, 2.5 miles across and 364 feet high, was completed in 1971 to supply cheap hydroelectric power to Egypt and Sudan. Lake Nasser, the impoundment on the Nile River, covers some 2,000 square miles.
Courtesy NASA

Han dynasty bronze tomb stove, made between 206 B.C and 220 A.D.
Courtesy Richard Sindler

POSTED 5 JULY 2001

Flat, fertile river valleys have long lured humans -- and people have lived along the Yangtze and Nile for thousands of years. Three Gorges will be the largest dam in history, and yet critics say China is spending only a fraction of what's needed to recover artifacts before the waters rise.

Dams flood evidence of the past. Roads pave it over. And buildings suffocate it under concrete. Whether it's a tunnel, a road or a parking lot, construction can obliterate clues to the past.

But construction can also reveal, thanks to state and federal mandates that builders engage in "salvage archaeology." As the name implies, salvage is a quick and dirty excavation of artifacts and other traces of human settlement, performed before the earth-movers move in.

I can dig it
These days, salvage archaeology often focuses on the daily life of average people. That was a traditional black hole of early archaeologists, who focused on kings and their courts, not commoners and humble crafts. Recent finds include:

A kiln built in 1774, excavated before a highway expansion in Trenton, N.J., contained hundreds of chamber pots, teacups and syrup jars. The dig showed the status of a state industry that eventually supplied toilets, china and stoneware to the nation.

Excavations in northern New Mexico contained artifacts from 1821, when the Santa Fe Trail opened and "New Mexico" was part of old Mexico.

Digs along Highway 71 in Nebraska - a state that helped pioneer salvage archaeology 42 years ago -- uncovered a paleontological trove of fossils from 20 million years ago. The fossils, including a new species of gopher, fossilized logs, and an extinct relative of deer and camels, went to the University of Nebraska State Museum.

A little squirt'll do ya. A pottery vessel is exposed in a shallow dig. Wetting helps bring out color on the ancient pot.

Salvage archaeology is a mixed blessing. You get the money -- and the earthmovers, which destroy or cover all traces of the past.

Since money for archaeology is always tight, the mandate to perform salvage archaeology before building federally-supported pipelines, powerlines and highways is "a tremendous boon to archeology," says Marlin Hawley, a Wisconsin archaeologist who directs salvage digs.

Effigy mounds are some of the most amazing ancient earthworks. What does salvage archaeology say about the builders of Wisconsin's Indian mounds?