 <unk> and Colonel Gerald Thomas , <unk> 's operations officer , believed that the Japanese attack would come at the <unk> Ridge , a narrow , grassy , 1 @,@ 000 m ( 1 @,@ 100 yd ) long , coral ridge ( 9 ° 26 ′ 39 ″ S 160 ° 2 ′ 50 ″ E ) parallel to the <unk> River just south of Henderson Field . The ridge offered a natural <unk> of approach to the airfield , commanded the surrounding area and was almost undefended . <unk> and Thomas tried to persuade <unk> to move forces to defend the ridge , but <unk> refused , believing that the Japanese were more likely to attack along the coast . Finally , Thomas convinced <unk> that the ridge was a good location for <unk> 's Raiders to " rest " from their actions of the preceding month . On 11 September , the 840 men of <unk> 's unit — including the 1st Raiders and the <unk> — deployed onto and around the ridge and prepared to defend it . 
