On the remoter frontiers the war was ruthless beyond measure.  Sir John Johnson devastated the Mohawk valley, in the present State of New York, and some of his prisoners were received at Carleton Island.  Of this inglorious warfare Haldimand’s secretary, Captain Matthews, wrote to Nairne a little later [17th June, 1780], “You will have heard that Sir John Johnson has executed the purpose of his enterprise without the loss of a man, having destroyed upwards of an hundred dwelling houses, barns, mills, stock, &c., and brought off 150 Loyalists, besides Women and Children.”  The worst outrages came from the Indian allies, of whom Nairne thought so badly.  From Niagara, on March 1st, 1779, Captain John MacDonnell wrote to Nairne of the terrible massacre at Cherry Valley, on the New York frontier, which excited horror throughout the colonies, and did much to inflame the hatred of the Americans for England.  Not, however, the English but the Indians were really guilty.  “There has nothing appeared,” wrote Captain MacDonnell, “on the theatre of the war of near so tragical or rather barbarous a hue; the reflection never represents itself to my view but when accompanyed with the greatest horrors; both Sexes, young and old Tomahawked, Speared and Scalped indiscriminately in the most inhuman and cruel manner.  But that there was all possible care and precaution taken to prevent them is undenyable.  Captain Butler, who had command of the expedition, was indefatigable in his endeavours and exertions to restrain and mitigate the fury and ferocity of the savages often at the risk of the Tomahawk being made use of against himself as well as the Indian officers....  Out of a hundred and seventy scalps three-fourths were those of Women and Children.”  Butler’s name is still looked upon in the United States as that of a fiend incarnate, but the testimony of his fellow officer seems to free him from blame for the worst of the horrors.  Both sides were bitter, but Nairne himself never shows any vehemence of passion.  In his view the war was a painful necessity, to be fought to the end without anger.

Late in 1779, Nairne was recalled from Carleton Island.  He reached Montreal on the 5th of December, and, two days later, secured leave of absence to look after his private affairs.  At this time General Haldimand had matured a plan to take advantage of the remote position of Murray Bay to confine there some of his American prisoners.  At Murray Bay they seemed particularly safe.  There was as yet no road over Cap Tourmente; in any case to go in the direction of Quebec would mean seizure sooner or later; to go in the opposite direction would be to perish in the wilderness; and the only outlet was by water across a wintry river some twelve miles broad.  On the 26th of January, 1780, Haldimand wrote to Nairne at Murray Bay that he was to erect buildings for rebel and other prisoners, and that, to do the work, some men were being sent down; he was to employ in addition as many of the inhabitants as he might think necessary.