'Woodlark' was a British operation by the Special Operations Executive to establish a base from which the Nordland railway in the Namdal, in the area to the north of Trondheim in German-occupied Norway, could be attacked (12 September 1944/8 May 1945).
The three-man party of H. Helgesen, O. Østgaard and O. Walderhaug was landed by sea on 12 September and by the end of the same month had been joined by another four men who had travelled overland from Stockholm in neutral Sweden. The party established a base just on the Swedish side of the frontier, but from an early stage suffered from internal conflict, and although Y. Øgarrd was delivered by parachute as the radio operator on 7 November he was never able to make contact. Supplies were short and there were several trips to Stockholm.
On 13 January members of the party attacked the Jørstad bridge, wrecking a German troop train. From this point, however, the party gradually broke up, had new leadership and increasingly played a subsidiary role in the area, although it marched into Steinkjær as a separate unit at the liberation.