PROSPECT HARBOR LIGHTHOUSE, ME. The light and fog signal were first established to mark the inner harbor’s east side entrance for the town’s large fishing fleet. Although the Lighthouse Board deactivated the aids in 1859 because the harbor was no longer being used as an anchorage during storms, the station was reopened in 1870.

The 1870 5th-order Fresnel lens was automated in 1934 and replaced with a modern lens in 1951.

http://www.cr.nps.gov/maritime/light/prospect.htm