ence with the Jim River. The study site lies at an elevation of 270 m approx- 

 imately 5 km from the mouth of Prospect Creek. The site was worked by scrap- 

 ing surface gravel deposits over 6 ha of gently sloping terrain adjacent to 

 Prospect Creek. In addition, a l-ha pit was excavated on the northern edge 

 (lowest point) of the gravel removal area to act as a sediment catch basin. 

 Gravel removal was conducted intermittently from April 1974 through April 

 1975 with 63,636 m of gravel removed for construction of the Trans-Alaska 

 Pipeline System. A 45-m wide buffer was maintained between Prospect Creek 

 and the gravel removal area, however, a 90-m wide swath was cleared through 

 this buffer zone on 22 May 1974. 



Gravel removal was accomplished by ripping frozen material prior to 

 conventional loading and hauling methods. Material varied from clean to 

 silty fine to coarse gravel. An average working depth of 2.7 m was planned 

 for the catch basin pit with additional excavation permitted if suitable 

 material was present below this level. A screening operation to produce 

 select material was conducted in the pit. 



The pit has filled with water as a result of intergravel flow during 

 the summer months. During the site visit, this ponded water averaged approxi- 

 mately I m in depth. The pit does not have an inlet, however, an outlet 

 leading to Prospect Creek from the northwest corner was constructed during 

 site rehabilitation activities to allow unimpeded fish passage into and out 

 of the pit. 



Additional rehabilitation measures included grading the material site 

 to I percent downslope, ensuring that al I cut slope faces were no steeper 

 than 2:1, and leveling of temporary stockpiles to blend with the natural 

 terrain. Various aspects of this site are shown in Figures 28 and 55. 



SOUTHERN INTERIOR 



General Description of Region 



All five study sites in the Southern Interior were located in the 

 Tanana River drainage, which empties into the Yukon River. The study sites 



58 



