midstream loafing sites but short gravel bars did occur at 

 intervals along both banks. Distance from the road was about 200 

 m but a well-worn trail followed the east bank. This trail was 

 screened from the river by the moderately dense growth of shrubs. 



Boulder River Survey Area 



The Boulder River was surveyed from Falls Creek campground 

 to Hicks Park campground. Total distance covered was 26.06 km and 

 elevation ranged from 1585 m (5200 ft) to 1932 m (6340 ft). This 

 equated to a mean gradient of 1.3% or 0.6 degrees. The specific 

 section of the river from which all harlequin duck observations 

 came (Figure 3) ran from approximately 4 00 m downstream of 

 Fourmile Creek to 300 m upstream of Clear Creek. The length of 

 this section was 5.14 km and the elevation ranged from 1865 m 

 (6120 ft) to 1914 m (6280 ft), for a mean gradient of 0.9% or 0.4 

 degrees. The channel meandered the entire length of the survey 

 area with the exception of Hell's Canyon, which is a straight, 

 narrow, bedrock canyon. This was the only section of the Boulder 

 River survey in which both banks approached the water at >45 

 degrees angle. Flow volume, measured on 5 September, was 24.95 

 cms (81.86 cfs) which was the lowest flow during the survey 

 period. Flow measurements were taken in the harlequin duck 

 observation area (Figure 3) . Stream flow data recored at the USGS 

 gauging station in Big Timber is included in Table 2. Similar 

 data from the Gallatin River are presented for comparison. 



15 



