Fletcher Lake is named after Robert Fletcher who operated an Inn near the eastern shore of the Lake. This was an important stop over for people travelling between Halifax and Truro. Travelers were able to have their horses cared for during their stay and then set off the next day.
A stream from Lake Thomas flows into Fletcher and there is a drop of approximately 10 feet. This meant that in order to enable the travel between the two lakes Lock 4 was built at the south end. The remains of Lock 4 which still stand are completely of stone and it is believed to be the same stone which was used during the first construction period (1826-31). Today to the west of Lock 4 is the stream but small craft still have to portage. On the east and west sides of the stream and the Lock are the remains of a stone dam which would have served to maintain the water level back to Lake Thomas.
The area rising up from the Lake shore on the west side was particularly important as its banks are composed of granite which could be quarried and used in Locks 4 and 5. As you look down Fletcher Lake toward Grand Lake you can see an island and behind it a stream with a railway crossing. This was one of several crossings which were built low enough to prevent the Canal from continuing to operate in the 1870s.