Archaeological investigations have uncovered substantial occupation debris across the island, including two sherds of distinctive 'Black' pottery that may be examples of 'Crannog Ware', artefacts now held in the National Museum of Ireland. These pottery fragments suggest the island served as more than just a convenient stopping point; it was likely home to a community that took advantage of its strategic position where river meets sea.

The island's archaeological significance was first documented in the comprehensive Archaeological Survey of County Donegal, compiled by Brian Lacey and his team in 1983. This survey catalogued field antiquities spanning from the Mesolithic Period through to the 17th century, placing Inish Samer within the broader context of Donegal's rich archaeological landscape. The presence of a midden, essentially an ancient rubbish heap that provides invaluable insights into past dietary habits and daily life, further reinforces the island's importance as a settlement site.

More recent archaeological work in 2003, conducted by Chris Read under excavation licence 03E0558, involved monitoring in the vicinity of the midden. Whilst this particular investigation revealed no additional archaeological features, the earlier finds continue to spark interest in the island's past. The pottery sherds, particularly if confirmed as Crannog Ware, would connect Inish Samer to the broader tradition of lake dwelling communities that flourished in medieval Ireland, suggesting this small island played its part in the complex network of waterway settlements that characterised the region.