Salt marshes in Maine exhibit somewhat mysterious features known as salt pannes. The purpose of this investigation was to attempt to discover the origin of these morphological features. To complete this investigation, a series of tests were done in two coastal salt marshes located in southern and mid-coast Maine. These included the retrieval of sediment cores, performance of standard grain size analysis on specific core samples, and rising head slug tests on selected bore holes. Results from these tests suppported two possible hypotheses. One may indicate an ancient lagoon located at the current site of the back barrier marsh. Through the accumulation of sediments, this lagoon constricted into a creek. Deposition of additional sediments eventually pinched off the creek end, forming a salt panne. The second scenario suggests that meandering tendencies of old tidal creeks isolated segments of the creek, which formed the pannes. Investigation of additional marshes in the region is required to gain further evidence for the formation of these features.