Visibility is also greatly reduced because of turbid 

 water. Any estimate made during years that had 

 heavy rains of long duration during the peaks of 

 spawning runs is not comparable with an estimate 

 made during normal water levels. 



Streams in which intertidal spawning pre- 

 dominates may present difficult observation condi- 

 tions at high tide. Spawning salmon in the inter- 

 tidal zone behave differently when the spawning 

 areas are flooded by the high tide. 



Aerial observations vary with the different 

 types of aircraft used. Observations made from small 

 light planes capable of following winding stream 

 courses are more reliable than those made from 

 larger planes which must fly at considerable height 

 above the stream and generally at greater speeds. 



descriptive names corresponding to location or other 

 distinguishing features. Some streams have identical 

 names; they are retained without change due to local 

 usage. Many minor streams have no names; hence 

 they are identified only by number. 



Stream number. --This number appears on 

 the right side of the first line of the heading. The 

 letter preceding the number designates the adminis- 

 trative district in Southeastern Alaska: e. g. , "WC" 

 for West Coast. Continuity of stream numbers along 

 a shoreline is followed where practical. Due to the 

 numerous islands, breaks in the sequence have been 

 necessary. A catalog number combining numbers 

 and letters designates a minor stream, either adjacent 

 to or between major streams numbered in sequence. 

 For example, stream number 18A is a minor stream 

 adjacent to major stream number 18. 



Physical Observations 



Observations of the characteristics of each 

 stream by different observers have been recorded 

 with varying degrees of accuracy. Many details of 

 stream descriptions are dependent upon the individ- 

 ual observer's ability and knowledge. 



Many stream dimensions are merely esti- 

 mates. Instruments for measurements were usually 

 not available to observers, and packing and esti- 

 mating were used. 



Most basic stream distances have been taken 

 from aerial photographs and are relatively accurate. 

 However, some errors may have occurred where re- 

 ference points were difficult to identify. Drainage 

 estimates were based on compensating polar plani- 

 meter measurements of valley areas, but occasion- 

 ally drainage divides were difficult to distinguish 

 and the areas given are only approximate. 



EXPLANATION OF CATALOG FORMAT 



Further descriptions of the data such as esti- 

 mates of timing, temperature ranges, spawning fa- 

 cilities, etc. , are included under these specific 

 headings in the explanation of the catalog format 

 that follows: 



ADF Statistical number. --A space for the 

 new ADF Statistical number is provided for use when 

 the new numbers are assigned. 



Latitude and longitude . — This appears on 

 the second line, left side, of the heading. Location 

 of streams is given by the use of "N. " for north lat- 

 itude, and "W." for west longitude, stated in degrees 

 C ), and minutes and tenths of minutes ('). Location 

 of the high tide point on the stream is given for 

 positive identification. 



Previous number. --This appears on the 

 second line, right side, of the heading. Stream 

 number or numbers used in the past by Fish and 

 Wildlife Service ore given for positive identifica- 

 tion of old stream records. 



Geographic location . --This appears on 

 the third line of the heading. Each stream location 

 is described by the administrative district, major 

 channel, bay or inlet, arm or cove, and location 

 within the smallest division given by direction 

 (from true north) and distance (nautical miles). 



Major species. --Included are those species 

 of salmon which furnish the bulk of spawning in 

 the stream. Where more than one dominates, both 

 (or more) are included. 



Stream Designations 



Statistical area number. --The number used 

 by the Alaska Department of Fish and Game to desig- 

 nate the statistical area is given in the upper left 

 side of the heading. 



Stream name . --This appears in the center 

 of the first line of the heading. Recorded names or 

 common local names are used when available. 

 Otherwide unnamed streams of importance ore given 



Other species. — This indicates other known 

 species of salmon and trout using the stream. 



Escapement timing. --The timing is based 

 on systematic stream survey records, which include 

 a number of years of surveys with visits before, near, 

 and after the peaks of abundance. Extensive stream 

 temperature studies were conducted in conjunction 

 with most of these surveys. The earliest runs of 

 salmon occur along the colder mainland streams. 

 The latest runs are in the outer channel and coastal 



