George A. “Frolic” Weymouth, 79, a prominent conservationist and artist who founded and chaired the Brandywine Conservancy & Museum of Art, died Sunday morning at his home in Chadds Ford, the conservancy said.

Chris Palmer writes today for Philly.com that Mr. Weymouth had been hospitalized recently for pneumonia, according to Andrew Stewart, a spokesman for the organization.

Mr. Weymouth, a member of the du Pont family, was a seminal force in preserving tens of thousands of acres of picturesque scenery around the Brandywine River in Pennsylvania and Delaware. He also was an accomplished painter and combined his passion for nature and the arts by helping to establish the Brandywine Conservancy & River Museum of Art in 1967.

Nearly 50 years later, the organization has protected 62,000 acres, and the museum, which houses 4,000 pieces of art in a renovated grist mill, has become world renowned for its galleries showcasing the work of the Wyeth family, whose members were close friends with Mr. Weymouth.