US Army Corps of Engineers
Sacramento District

image - construction at Folsom Dam

Sacramento District archaeologist helps preserve “layer cake” of history

Published Aug. 18, 2014
Steve Pappas, ECORP Consulting field director, answers questions from members of the U.S. Army Corps of Engineers Sacramento District regulatory team during a visit to an archaeological dig near El Dorado Hills, Calif., July 31, 2014. ECORP has been contracted to help research and catalog historic sites on this project site.

Steve Pappas, ECORP Consulting field director, answers questions from members of the U.S. Army Corps of Engineers Sacramento District regulatory team during a visit to an archaeological dig near El Dorado Hills, Calif., July 31, 2014. ECORP has been contracted to help research and catalog historic sites on this project site.

Lisa Westwood, ECORP Consulting archaeologist, stands above an abandoned well July 31, 2014, that was part of an 1800s inn that catered to miners outside today’s Northern California town of El Dorado Hills. ECORP has been contracted to help research and catalog historic sites on this project site.

Lisa Westwood, ECORP Consulting archaeologist, stands above an abandoned well July 31, 2014, that was part of an 1800s inn that catered to miners outside today’s Northern California town of El Dorado Hills. ECORP has been contracted to help research and catalog historic sites on this project site.

Representatives of participating developers and the U.S. Army Corps of Engineers Sacramento District regulatory team visit a site July 31, 2014 on the “Folsom South of 50” project that features remnants of an inn that catered to miners and others traveling between Placerville and Sacramento, Calif., during the 1800s.

Representatives of participating developers and the U.S. Army Corps of Engineers Sacramento District regulatory team visit a site July 31, 2014 on the “Folsom South of 50” project that features remnants of an inn that catered to miners and others traveling between Placerville and Sacramento, Calif., during the 1800s.

LiDAR laser imaging allows archaeologists to view land features hidden by heavy vegetation, as demonstrated in this image comparison. The top half of the image is standard aerial photography, whereas the LiDAR image in the bottom half exposes evidence of tailings and other erosive actions from hydraulic mining in property adjacent to the “Folsom South of 50” project. (Imagery courtesy of ECORP Consulting, Inc. and Easton Development Company)

LiDAR laser imaging allows archaeologists to view land features hidden by heavy vegetation, as demonstrated in this image comparison. The top half of the image is standard aerial photography, whereas the LiDAR image in the bottom half exposes evidence of tailings and other erosive actions from hydraulic mining in property adjacent to the “Folsom South of 50” project. (Imagery courtesy of ECORP Consulting, Inc. and Easton Development Company)

SACRAMENTO, Calif. – Over 1,900 acres of Northern California property located between Folsom and El Dorado Hills is like “a layer cake of modern history,” according to Erin Hess, an archaeologist with the U.S. Army Corps of Engineers Sacramento District Regulatory Division.

“This area includes everything from remnants of placer mining, hydraulic mining, dredge mining, dairy operations, roadside inns from the 1800s all the way up to Cold War-era missile research facilities,” said Hess.

All this history is part of the “Folsom South of U.S. Highway 50 Specific Plan” project area. Mitigation agreed to by the developers includes having the history of this area surveyed and cataloged.

When permits from the Corps are required for a development project and eligible historic resources could be affected, Corps regulators become involved through requirements of Section 106 of the National Historic Preservation Act.

Since being called in, Corps regulators and project applicants have worked to identify possible historic sites, consulting with local residents, Native American tribes and historical societies in order to evaluate properties for historic significance.

The jigsaw puzzle of an area’s history must be carefully pieced together. A trash pit filled with tin cans was first thought to be evidence of a mining camp, but the artifacts were later determined to be remnants of a more recent dairy operation.

Modern technologies aid in documenting extensive historic sites. LiDAR aerial imagery showed how this area’s topography was changed by dredge tailings and hydraulic mining operations.

LiDAR measures distance by illuminating a target with a laser and analyzing the reflected light. LiDAR can map features beneath plant cover and provide an overview of broad, continuous features that may not be obvious on the ground. This imagery helped Corps archaeologists pinpoint the best sites for exploratory excavation.

Once research is complete, local historical societies will be given access to the data gathered at this site, said Hess. Some historic content, once cataloged, may be capped with soil for preservation.

Physical history in the Old West changed whenever people’s fortunes changed and that is reflected in the “South of 50” properties.

Mining ditches were transformed into irrigation ditches after mining hopes played out and farming took its place. Materials that were hard to come by were reused. Building stones often became fence material after a home or business was abandoned.

“In modern archaeology, a lot of the digging is done in libraries,” said Hess. Mountains of research are often collected before the first actual field trip to the location.

Legislation mandates this archaeological work be done, but it comes with a positive benefit for developers. “Preserving a historic site can add to an area’s unique attraction,” said Hess. “It can increase tourism as an attractive amenity on the property.”