Some things to note, those are four foot pulp logs going to a pulp mill. Saw logs would be longer and a lot harder to drive as they get jammed up. Most of the big drives in northern New England were pulp related. The odd thing is they show what appear to be both hardwood and softwood logs. Berlin NH was the only mill actively pulping both hardwood and softwood (they developed a lot of the technology for pulping in general and hardwood in particular). My guess is the film came from the Brown Company archives . Brown Company supplied Kodak paper for some of the first consumer cameras and had a company photographer, a very small portion of the photo archives are at this link
https://cdm15828.contentdm.oclc.org/digital/collection/p15828coll3 . Brown Company is long gone, the former mill site in Berlin now has the biggest biomass power plant in the Northeast. The boiler was made out of parts of the former chemical recovery boiler. There are still stacks of wood there but instead of logs its biomass chips.
There were saw log drives earlier but if wasnt until the big demand for paper when the river drives got big. The mill I worked for in Berlin NH stopped their drive in the 1960s, there were still drives on the Kennebec in Maine until the 1970s, as a kid I remember heading up RT201 and looking out at a river full of logs. Geat Northern Paper in Millinocket was still using the river to store logs until the late 1980s. The clean water act and water quality regulations is what shut them down. Early in my career I worked with an old timer who was a dam engineer for the mill in Woodland Maine, he would go out in the woods for the winter with a crew and would build or rebuild various types of dams used to store up water for the drive. It was an art, many of the streams used to drive pulp may be a couple of feet wide during the summer but they would build up enough water upstream to get the stream flowing wide and deep enough to get the logs down to a large stream before they ran out of water.
Our mill in Berlin NH shared the river with a couple of other mills, both mills used the river to drive and store the logs until they could pull them out of the river. Every log was stamped with a symbol denoting the owner of the log and they were sorted between the two mills, For several miles north of town the mills built stone piers in the middle of the river and strung boom chains between them. One side of the river stored logs for one mill and the other side was for the other mill. The bottom of the river and lakes are loaded with sunken pulp logs all the way to Canadian border 30 to 40 years after the end of the drives. Every year when the river get low or one of the many hydro dams is being worked on and they draw down the river, many 4 foot pulp logs appear along the banks. The hydro dams all have trash racks upstream of the turbines and they end up cleaning out a fair share of these logs. The company stamps on the butt of the logs are frequently still visible.
It was a tough life for the woods crews and drivers, more than a few were buried where they died in a drive. The crews didnt get paid until the end of the drive, many would get their pay, head into the nearest town and drink, gamble and hire a local prostitute and burn up their seasons pay in a couple of days. They might get odd work during "mud season" after the drive working to "straighten" out the local rivers and streams and then would go back in the woods when things dried up to start cutting next years wood. Some of them made it to old age but many didnt.
If you are into history this book is pretty well the best regarded on the history of logging in the Northeast
Amazon product ASIN B00PN21RTS . The author had several books that covered the drives in the region