'Donald' was a US special forces operation to parachute an 11-man Office of Strategic Services operational group into the Finisterre area of German-occupied France to secure US lines of communication (5/17 August 1944).
A four-man reinforcement team was dropped into the same area on 6 August.
At this time the Brittany peninsula was being cut off at its base by US troops, and another column was moving west along the north coast from St Malo toward Brest. To facilitate the passage of the former column resistance groups were instructed to preserve bridges, railroads and highways along east/west routes in the northern part of Brittany, and to begin maximum guerrilla activity. The task of the 'Donald' group included protection of the railway viaduct to the east of Guimiliau.
Of the three Short Stirling adapted bombers scheduled for this mission, one could not take-off as a result of a defective wheel, while of the other two aircraft one could not recognise the drop zone signal and returned to its base at Harrington in the UK. The third aeroplane made the drop in the clear night from a height of 800 ft (245 m) at 01.30 on 6 August, and the men of the operation group landed safely without sustaining any injuries, but over a large area. The group was assembled with the aid of the local resistance movement at a safe house, where it was fed and accommodated in a hayloft. An early problem was the group’s radio equipment did not arrive.
On 7 August the group moved to the bridge which was to be protected, a journey of a mere 10 minutes, over the Pense stream. The bridge was large, with seven brick and stone piers, and after the defence arrangements had been organised, the group handed responsibility to the local resistance.
On 9 August Capitaine Cadalen, the leader of the local group of the Forces Françaises de l’Intérieur, and 250 of his men accompanied the group to Landivisiau, which the Germans had left on the previous day. The group’s arrival was occasion for celebration, and here the group met an advance unit of the US Army, whose radio transmitter failed to reach London.
On about 11 August the group continued to Lesneven, where it contacted advance elements of the US Task Force 'A' under the command of Brigadier General Herbert L. Earnest, who asked the group to return to Landivisiau to protect the town’s inhabitants from German harassment. The group got as far as far as Guiclan, where it captured 22 Germans and was reinforced by three US soldiers, in a Jeep carrying a 0.5-in (12.7-mm) machine gun, who had become lost. Moving to Roscoff on the northern coast, where Germans had been reported, the enlarged force found a block house impregnable to anything but artillery. A German soldier on a bicycle was sent back to the block house to tell its little garrison to surrender. The Germans agreed, but emerged from the block house with weapons. The maquis fighters opened fire on the Germans, who then fell back into the block house. When threatened with artillery fire, the 30-man German garrison came out unarmed.
On 13 August, while heading to Morlaix, a patrol of the group met an officer from a nearby 'Jedburgh' party, and this Lieutenant Chadbourne established contact with London to request weapons for the resistance fighters, but none arrived in the following few nights.
On 17 August a US civil affairs team reached the area and took over the operational group’s functions, and during the next two days the operational group’s personnel travelled to Cherbourg, from which an aeroplane took them to England on 19 August.