42 



To the former, however, the abundance of rain in this 

 region is an inconvenience and often depressing, but, once 

 this condition is accepted, the superb scenery is in itself 

 ample reward for the journey. 



The characteristic surface features of this belt are its 

 coasts, its fiords, its valleys, its drainage, its glaciers, and 

 its mountains. The coasts are irregular in outline and 

 generally abrupt and mountainous even to the water's 

 edge. Occasionally, however, low lying forelands fringe 

 the base of the mountains, as at Gravina island, and often 

 extend as a reef for some distance from the shore, where 

 they become a menace to navigation. In the Glacier Bay 

 region submerged tree trunks prove that the coast is sinking 

 relatively to sea level, while on Admiralty island recent 

 fossils have been found in a bed of blue clay 200 feet (60 

 m.) above tide water, thus indicating a rise of the coast 

 since the recession of the ice. It would appear, therefore, 

 that the coast has undergone both positive and negative 

 changes since the Glacial epoch. The coasts are generally 

 heavily covered with dense forests which, notwithstanding 

 the lack of proper subsoil which was entirely removed by 

 the ice, are so thick and luxuriant that the geologist is 

 forced to confine his reconnaissance study of the region 

 to the immediate shore outcrops between high and low 

 tide water marks and to the uplands above timber limit, 

 2,000 to 3,000 feet (600 to 900 m.) above tide water. The 

 fiords are deep and are characteristically trough-shaped, 

 Their flat floors are in places cut below grade in their 

 central portions and relatively shallow near their mouths, 

 and are soft and evidently covered with glacial debris. 

 The best halibut fishing is found on these terminal sub- 

 merged sandbanks. Many of the fiords are remarkably 

 straight and trend either in a northerly or a northwesterly 

 direction. The longest fiord is Chatham strait with its 

 inland extension, Lynn canal. It is about 250 miles (400 

 km.) long, 3 to 6 miles (5 to 10 km.) broad, with a depth 

 of 1,000 to 2,500 feet (300 to 750 m.), and traverses the 

 general trend of the bed rock structure at an angle of about 

 30 degrees. Both the topography and geology indicate 

 that it owes its position to a great structural fault. Many 

 of the other fiords also follow structural lines in the bed 

 rock formations. Other important fiords are Portland 

 canal, Clarence strait, Behm canal, Taku inlet, Glacier 

 bay, Icy strait, and Cross sound. The evidence at present 

 available indicates that practically all the fiords are simply 



