Park chairman Jody Grant called it a "momentous" gift during the press conference at the park's offices, from which Robert and Sam are sending in updates. It's "a major step" in funding the new bridge between Uptown and downtown, Grant said.

Joined by Mayor Leppert and a handful of city council members, JPMorgan Chase CEO Jamie Dimon spoke about the donation, saying, there's "nothing more important a bank does than support the community it's in." Repeating a popular line about a park that exists so far only in artists' renderings and traffic delays, he added, "Dallas has created something out of nothing."

More details and photos from the announcement will follow shortly.