This species is still only found on a few chalk grassland sites in Cambridgeshire, with most locations matching the historical literature, including Devil’s Dyke, as recorded by Jenyns. Changes in management at Devils Dyke in the 1980s saw numbers dwindle close to extinction, but concerted efforts have reversed that decline and the chalkhill blue is now counted there in the thousands. The species has also naturally spread to recolonise Fleam Dyke and the Roman Road and has been introduced to the limestone grassland at Barnack Hills and Holes.