Fifty years ago today, the Town of Bovina celebrated it's Sesquicentennial. From all information I can find, this was the first time the Town of Bovina had celebrated a milestone anniversary. There is no evidence of a town centennial celebration in 1920. Interestingly, the Bovina UP Church did celebrate such anniversaries since its centennial in 1909, including 125th, 150th, 175th and its Bicentennial in 2009.
Here's a newspaper ad for the day's celebration.
And some of the pictures I have collected from this celebration are on the Bovina NY History Flickr page at: https://flic.kr/s/aHsmNL4BpF
If you have pictures from this celebration I'd love to get scans or copies of them.