The last reconnaissance on Guam was conducted by a mechanized reconnaissance-in-force. A force consisted of Alpha, Echo (Scouts), and H&S Company of 3rd Tank Battalion; and I Company of 21st Marines. During the last major actions beginning 3 August 1944, the 1st Battalion, 9th Marines (1/9) had secured a series of roads that junctioned in Finegayan Village, in the northern section of the islands. Lieutenant Colonel Hartnoll J. Withers led the group, moving north-northwest. Two M3 Half-track, two jeeps for communications purposes and one platoon of tanks supported by an infantry platoon were maneuvering toward Road Junction 177.