Huntersland School, Schoharie County New York.
Also the photographer is stamped on the reverse: P. J. Messer so we should be able to determine when he or she was in business.
Teacher Stanley Heason, Huntersland School
Back row left to right: Judy Shufelt, Eula Sison, Hattie Conklyn, Ernest Utter, Hazel Laraway, Walden McCumber, Mildred Laraway, Ruth Cook
Second row: [? can't read] Becker, Minnie Heason, Ros-- Coons, Mae Acker, Grant Laraway
Front row: Beatrice Spencer, Manyard? Laraway, - Cook, - Shufelt
Census records on Ancestry indicate that Stanley (the teacher) and Minnie Heason were the children of George & Isadora Heason and lived in Middleburgh New York. Stanley was born ca 1890 and Minnie ca 1901. Minnie looks to be about 12 years old in the photograph, giving us an estimated year when it was taken of circa 1913.
Next I found Manard Laraway born in 1905 living in Middleburgh. He looks to be about 10 years old in the photo so that would give an estimated year of 1915 for the photo
* Grant Laraway was born ca 1902 and is in Middleburgh
* Walden McComber was born ca 1897 and lived in Middleburgh. I'd estimate he is no more than 16 years old in the photo, dating it to ca 1913
Hairstyles of the girls suggest pre 1920, perhaps around 1915 or so.
Clothing is a mixture of periods and I suspect that may be due to a number of reasons - some children may not have had current fashions to wear. Older students, girls especially, might have known it was picture day and parents may have suggested they wear mom's best Sunday dress or skirt and blouse. This would put those girls in earlier fashions. Some children could be wearing older siblings hand-me-downs.
However we can look at one distinctive feature - the V-necked yoke worn by three of the younger girls, then do some research to find out when this style came into fashion. That would allow us to determine an earliest date when the photo was taken.
We should also note the below-the-knee knickers that the young boys in the front row are wearing. One also looks to be holding a newsboy style cap. This helps confirm an estimated timeline for the photograph of 1910-1915.
This is not my time period of expertise, as I focus on Civil War era photographs. The best guess I can come up with for this photograph, using hairstyles, clothing and census records, is between 1910-1915 and probably closer to 1915. I'd love to hear from readers who may have a better estimate than I do for this time period, or who are familiar with an individual in the photo.