398 The National Geographic Magazine 



rush to Alaska, some additional map- 

 ping in the Copper Valley was done by 

 army officers and by prospectors, and 

 especially by Schrader and Mahlo, at- 

 tached to Military Expedition No. 1. 

 This work was confined, however, to 

 the district south and west of the moun- 

 tain group and added little to our knowl- 

 edge of their geography. In 1899 a 

 journey was made, which in its daring 

 and success equals those of Allen , Hayes, 

 and Schwatka as a geographic feat. 

 The distance covered was not nearly 

 so great, but the time consumed was 

 also much less. Oscar Rohn, topog- 

 rapher and geologist to the military ex- 

 pedition under command of Captain 

 Abercrombie, with a small pack train, 

 penetrated for the first time with ani- 

 mals the rough country lying between 

 the Chittyna River and the south slope 

 of the Wrangell Alps. Reaching the 

 Nizina or north fork of the Chittyna in 

 September, and seeing, as he thought, 

 the possibility of crossing the range to 

 the north of him by way of one of the 

 glaciers tributary to this stream, Mr 

 Rohn sent the pack train back to Valdez 

 and with one companion, Mr McNeer, 

 started across the mountains. The pass 

 at the head of the glacier proved to 

 be 8,000 feet above sea-level, and the 

 distance from the beginning of the 

 journey over the ice on the Nizina side 

 to its end at the source of the Chisana 

 (Tanana) was nearly 50 miles. The 

 route, the character of the ice to be 

 traversed, the distance, and the point 

 to be reached on the other side were 

 unknown. After 1 5 days on the glacier 

 and many delays from the storms which 

 prevail at this season of the year in 

 these latitudes, the two explorers found 

 themselves at the source of the Chisana, 

 the eastern fork of the Tanana, nearly 

 out of supplies and with a difficult and 

 little-known region separating them 

 from the Copper Valley. On foot, and 

 carrying their light outfit, they crossed 

 Cooper Pass to what the}' hoped would 



be the Copper, only to find that it was 

 the Nabesna, the great western fork of 

 the Tanana, and that the Copper was 

 still to the west of them. Ice was form- 

 ing in all the streams and snow lay 

 thick in the passes, but with the aid 

 of natives the}' reached the Copper in 

 early October, Copper Center a week 

 later, and crossed Lowe River divide to 

 Valdez through 3 feet of new snow on 

 the 25th. This work, although a recon- 

 naissance, added valuable details to our 

 knowledge of the northern and southern 

 flanks of the Wrangell Mountains. 



All of the work which has been out- 

 lined, up to the close of the season 1899, 

 was general in its character. Allen had 

 indicated the presence of five great peaks 

 in the Wrangell group where four ex- 

 isted, and his longitude was in error by 

 30 minutes. Mahlo, in 1898, corrected 

 much of this error in longitude, but 

 since he descended the Klutena to Cop- 

 per Center, and then went down the 

 Cooper, he could add little to the geog- 

 raphy of the mountain group proper, 

 which lay well to the northeast of his 

 route. Rohn, in his work along the 

 southern flank of the range, sketched 

 details previously unknown there, and 

 in his trip from the Nizina to the Tanana 

 studied a high area which is not likely 

 to be investigated soon again. Peters 

 and Brooks, during the same year, con- 

 tributed to our knowledge of the Chisana 

 and the Nabesna and outlined the north- 

 ern edge of the range. 



In 1900, however, Messrs Gerdine and 

 Witherspoon, of the U. S. Geological 

 Survey, as members of a party in charge 

 of Mr F. C. Schrader, carried a stadia 

 line into the interior from a Coast Sur- 

 vey base on Prince William Sound. 

 From locations given by this line a tri- 

 angulation network was expanded and 

 extended eastward over practically the 

 entire valley of the Chittyna and its trib- 

 utaries. For the first time Mount Black- 

 burn was measured accurately, and the 

 topographic features of all this southern 



