This report describes the results of the archaeological investigation of a wetland site at Ballynaclogh townland, Cappataggle, Co. Galway, on behalf of N6 Construction Ltd, during construction of the M6 Ballinasloe–Galway motorway scheme (Illus. 1 and 2). The site was discovered during monitoring of earthworks operations at construction stage. (The area was excluded, for ecological reasons, from the very extensive preconstruction archaeological investigations commissioned by Galway County Council on the motorway scheme.) An excavation was carried out between March and October 2008 by The Archaeology Company Ltd, employed by N6 Construction Ltd. It was directed by Michael Tierney under Licence Number 08E3874 and Ministerial Directions Number E3588, as issued by the National Monuments Service of the Department of Environment, Heritage and Local Government (now the Department of Arts, Heritage and the Gaeltacht). The Archaeology Company ceased trading prior to the completion of post-excavation analyses and reporting on the project. The finds and records were recovered by NRA Archaeologist Jerry O’Sullivan in 2011. The present authors, Clare Maginness and Jean O’Dowd—who had been the excavation supervisors at Ballynaclogh—were then commissioned by N6 Construction Ltd, in collaboration with the NRA, to complete the reporting and analyses resulting in this report.