The Geology of Saint-Gaudens National Historical Park, New Hampshire

The garden and a view of Mount Ascutney. Image from the National Park Service's page.

Saint-Gaudens National Historical Park lies along the Connecticut River just north of Cornish, in Sullivan County, New Hampshire. Established on May 30, 1977, it covers about 77 hectares (190 acres) and preserves the home, studios and gardens of Augustus Saint-Gaudens, America's foremost sculptor of the late 1800s and early 1900s. He was also a teacher and champion of other artists who won international recognition for American art, and he helped found the Cornish Colony, an artists' community known for modernizing classical European art and architecture and applying them in America. The park, a living memorial to him, holds more than 120 original sculptures — the largest collection of his work in the world.

The National Park Service's Geodiversity Atlas summarizes the park's geology, drawing on the Geologic Resources Inventory.

The rocks beneath the park

The park lies in the Connecticut River Valley, in the New England physiographic province, and shares its geologic history with a much larger region. The area's bedrock is Paleozoic, from the Ordovician through the Devonian. Under the park itself it is entirely metasedimentary — sedimentary rock changed by heat and pressure — in two formations:

• Waits River Formation (Silurian–Devonian), in the western half of the park: interlayered schist, phyllite, quartzite and impure limestone or marble.
• Gile Mountain Formation (Devonian), in the eastern part, beneath Saint-Gaudens' home, studios and gardens: mostly quartzite and granofels — metamorphic rock without distinct layering or alignment — interbedded with slate, phyllite or schist.

Blow Me Down Pond, on the park boundary. Image from the National Park Service's page.

Maps and reports

The Geologic Resources Inventory, which makes digital geologic maps and reports for more than 270 natural-resource parks, has products for the park on the NPS DataStore, where the park's completed soil resources inventory is also available. The park describes its natural features and ecosystems on its own site.

Sources

• National Park Service: "NPS Geodiversity Atlas—Saint-Gaudens National Historic Park, New Hampshire," citing Walsh (2015), Walsh and others (2020) and National Park Service publications (2015, 2016).