You are correct, the Morse bridge burned years ago. The footbridge is not covered. The stream is a little slow not, but it is right in town and easy access from either side most days.
Yes, the Robyville bridge is 15 miles northwest of Bangor via Broadway/Rt. 15. The cache thre is still active.
Robyville Bridge (GC1P43J) by Moonsouth (2/2)
The bridge hollora mentioned is at N 44 47.093, W 68 48.343. It is a modern built bridge, but built like an old one - Less than 10 years old?). It was never used for road traffic. The museum is nice to visit as well if you are ever in the area with time to spare. The cache near it is Geo Post Office and Travel Bug Hotel, Bangor (GCWEN7) by We3Beans (1/1.5)
Thanks for reminding me of that bridge, Hollora, I should add that to my list.