Sunnyfield is still there, on Rt 172 just south of Bedford Village.
Lendon Gray’s dressage barn was based there for many years, but I believe she has cut back on her operations recently.
I do not know how old your friend is, but I first rode at Sunnyfiled in the mid 60’s, and my first horse came from Sunyfield. It was built, and owned, by Mrs (Josephine ?) McIntosh, who was an A&P heiress. She had some of the first Lipizzaners in the US, and also some of the earliest “English sport” Quarter Horses. It was the original home of the USET, before the facilities at Gladstone and Hamilton were built.
Mrs McIntosh’s daughter, Karen McIntosh Collins competed on the US Olympic Dressage team at either Rome or Tokyo- I forget which. Mrs Mcintosh also had some serious open jumpers, and there was the remains of an upper level Three-Day Eventing course on the property. Quite a number of the top eventers of the 50s and early 60s rode there, including Mike Page, and Denis Glaccum.
In the mid 60s, Mrs McIntosh developed Leukemia (though it was not made public at the time) and she began selling off the youner-to middle aged horses, and made retirement arrangements for the older horses. That was when we bough Golden Rocket for me, and a year later Meadow Lark for my sister.
After she died, it was bought by someone else, and focused on show hunters. later the primary focus was dressage, but I do not know much about the intermediate stages.
I have a book with pictures of Sunnyfield in the early 60s.