The Geology Beneath Vanderbilt Mansion and the Roosevelt Sites at Hyde Park

Vanderbilt Mansion National Historic Site is one of three national historic sites along the Hudson River Valley in Hyde Park, Dutchess County, New York, managed together as Roosevelt-Vanderbilt Headquarters. The other two are:

• Eleanor Roosevelt National Historic Site, authorized on May 26, 1977, about 180 acres (73 hectares) preserving Val-Kill Cottage — First Lady Eleanor Roosevelt's retreat, office and home;
• Home of Franklin D. Roosevelt National Historic Site, designated on January 16, 1944, nearly 850 acres (344 hectares) preserving the birthplace and home of the 32nd president and the first U.S. presidential library.

The Hudson River seen from Vanderbilt Mansion. Image from the National Park Service's page.

The bedrock

The three sites lie in the Valley and Ridge physiographic province of eastern New York. Their bedrock is made entirely of Ordovician sedimentary and metasedimentary rocks, covered in places by younger Pleistocene deposits.

The glacial finish

Over that bedrock lies loose glacial till, left as glaciers advanced and retreated across New York during the Pleistocene. The ice planed down the landscape, producing the rolling hills and low ridges that characterize the three sites today.

Vanderbilt Mansion and its grounds. Image from the National Park Service's page.

Part of a larger region

The sites share their geologic history and several characteristic formations with the wider Valley and Ridge province. The NPS Geologic Resources Inventory has produced digital geologic maps and reports for the park, and a soil resources inventory has been completed; both are available through the NPS DataStore.

Sources

• National Park Service: "NPS Geodiversity Atlas—Vanderbilt Mansion National Historic Site, New York," citing National Park Service (2017).