Prior to a proposed extension to Crag Nook Quarry, Lazonby, Cumbria, Greenlane Archaeology was commissioned to carry out an archaeological desk-based assessment and walkover of the site. The work was undertaken in December 2022 and January 2023. The site comprises c2.8ha on the east side of Lazonby Fell, c2km west of Lazonby. The HER records six sites of archaeological interest, including post-medieval quarrying activity on Lazonby Fell and finds of Neolithic and Bronze Age date, although the exact location of some of the find spots is unrecorded. The site partially overlaps a large area of quarrying identified on the HER (Gazetteer Site 5). The documentary evidence, specifically early maps, show that these quarries were in existence from the late 19th century, although the only other documentary references to them are mid-20th century. The walkover survey identified 18 specific sites of archaeological interest inside the proposed area of the quarry extension or immediately adjoining it. All of these related to historic quarrying and most were located within the large area represented by Gazetteer Site 5. Based on the results of the desk-based assessment and particularly taking into account sites of archaeological interest within the wider area, including earthworks of probable late prehistoric late elsewhere on Lazonby Fell and the Roman site at Old Penrith, the site is considered to have slight potential for previously unknown archaeological remains to be present, specifically of prehistoric date, while further remains of post-medieval date are very likely but they would undoubtedly relate to quarrying. The presence of extant quarrying-related sites of post-medieval date, including quarry scoops, retaining walls, spoil heaps and associated structures, was confirmed by the walk-over survey; however, the significance of these sites overall is low and none are considered worthy of further archaeological work.