Landscape Architect for Idle Hour?

Did William K. Vanderbilt or his architect, Richard Howland Hunt employ a landscape architect when the second and currently standing Idle Hour Mansion was built in 1900-1904? This was common practice at the time, but I have never heard a name associated with the Idle Hour Estate. Could it be that the landscaping was mostly kept in tact from the first Idle Hour Mansion? If so, who was that landscape architect in 1878-1880? (Richard Morris Hunt was the architect of that mansion.)