I couldn't tell you from personal experience as my girlfriend and I got in free (using our tribal IDs), but from the website: Thanks to the generosity of Machias Savings Bank, admission to the Museum is free February 2 - April 30 and again November 2 - December 22, 2017. Admission fees from May 1 - October 31, 2017, are as follows: Adults: $8 Children 11-17: $4 Children 10 and under: Free Includes admission to the Abbe at Sieur de Monts Spring $1 discount for seniors FREE admission to Native Americans and Abbe members
From what I remember, it varies based on the exhibit. It was one of the more expensive museums I've been to and it severely lacks in content
I think it was around $14 and you could visit both abbe museums with the ticket.
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