IAC carried out the Phase 1 pre-development archaeological testing (58,000sqm trenches) within the 18km route corridor of the Dundalk Western Bypass and link roads. Testing revealed 34 archaeological sites which were subsequently excavated between 2002 and 2003 with a team of 95 archaeologists.

The excavations uncovered settlement/habitation sites from every period, and places of burial dating to the Bronze Age, Iron Age, early medieval and post-medieval periods. The outstanding sites were a Neolithic embanked enclosure at Balregan 1, a large Bronze Age funerary complex at Carn More 5 (comprising a barrow, a flat cemetery with 11 cist and three pit burials and two ring-ditches), an early medieval cemetery settlement at Balriggan 1, and a later medieval earthwork fortification on Fort Hill. The well-preserved and beautifully constructed souterrain at Newtownbalregan 6 was also significant.

A museum exhibition of the findings of this scheme was staged at the Louth County Museum, Dundalk and a full publication has been produced.