looks like it was the Payseur family that originally owned and built the 'Biltmore' hotel and pool
The Vanderbilt family claim that a mansion called Biltmore is their country home. Not true. Biltmore was constructed by the Payseur family as a hotel in the 1880s and it was operated by the Payseur trustees, the Vanderbilts, on a 99 year lease.
Payseur history
https://thefullertoninformer.com/a-history-lesson-you-were-never-taught/