For a great overview of the Belfast & Moosehead Lake, check out the Central Pacific Railroad Photograhic History Museum.
In the 1960’s, Belfast Maine was nicknamed the “Chicken Capital of the World.” The Belfast & Moosehead Lake was busy handling inbound feed for the chickens, along with assorted other traffic.
Here is a collection of cars on hand at Belfast for several days in 1968. Customers included Maplewood Poultry & Penobscot Poultry (crates and poultry byproducts), Consumers Fuel (propane and coal), Mathews Brothers (lumber), Viking (lumber), Belfast Canning (fish, probably sardines), and the City of Belfast (chloride). Several feed mills received soy, corn, and feed.
Below is a page of what appears to be the Burnham Jct. train register. Burnham Jct. was the west end and the connection with the Maine Central. While the year is not listed, I suspect that it is also 1968 since the dates match the dates of the cars on hand forms.