Until the big water company reservoirs were built in the 1930’s, New Hartford had only an assortment of small ponds and rivers to swim in. Greenwoods pond served the town center admirably; it was a large mill pond (really at two miles long it was a lake) created by damming the Farmington River.* There were other assorted mill ponds throughout town and deep curves of the Nepaug River, swimming holes in fact. However, there was also West Hill Pond. Although a dam added height, this was and is a natural pond of substantial depth. Spring fed it is very cold and very clean, even today. Pre World War II, there was almost no development on it (there is now!!).
The lake is on the next hill over, and a series of roads has linked Town Hill and West Hill since New Hartford’s founding.* Until the early twentieth century there was a very direct road, since abandoned. But even today along several twisting roads it is an easy ride with a horse. Until the 1950’s/early 1960’s, Esperanza owned two large pieces of the shoreline: ‘Boys and Girls Points’. These pieces were given to the Boy Scouts’ Camp Sequassen and remain part of the camp today. Until that time, camping and swimming at West Hill featured prominently in the summer activities.
I can only identify the person paddling past on the log in the background: Eileen Creevey Hall. The photo is circa 1920-23
*Greenwoods pond vanished entirely in March 1936: a flood took out the dam, which was 32 feet high and 200 feet long); along with the pond went a good chunk of the town.
*Yes, there is an East Hill!
Acair Fearann 
The bathing caps do make identification a bit difficult… they are swimming at the Boy’s Point. The points were so called because, when they camped there or change their clothes, the boys camped at the Boy’s Point, the girls at the Girl’s… singular lack of originality!
I’d make a photo guess, again, that the young man directly facing the camera in front of Eileen is Kennedy Creevey.