Vegetative clearing, overburden removal, and berm construction were 

 conducted at each of the three gravel removal areas. At the upstream area 

 the overburden was formed into an earthen dike, the purpose of which is 

 unclear. The gravel removal areas were not rehabilitated following distur- 

 bance. Various aspects of this site are shown in Figures 37, 42, and 48a. 



Sagavan irk tok River. The Sagavan ir k tok River is a large, sinuous river 

 (at the study site) which originates in the Philip Smith Mountains of the 

 Brooks Range at an elevation of approximately 1,500 m and flows through 

 mountains, foothills, and coastal plains approximately 300 km before enter- 

 ing the Beaufort Sea. The study site, at an elevation of 335 m, is located 

 about II km downstream from Pump Station Number 3 on the Trans-Alaska Pipe- 

 line, 16 km downstream from the mouth of Ribdon River, and 21 km upstream 

 from the mouth of Lupine River. 



Gravel removal occurred in 1974 and 1975 by scraping vegetated and 

 unvegetated gravel bars totaling approximately 35 ha. About 15 ha had been 

 vegetated with mature riparian willow thickets. The original mining plan 

 cal led for scraping to an average of 1.5m in depth with an average of 15 cm 

 of overburden removal required prior to gravel extraction. Approximately 

 283,000 m and 148,000 m of gravel were removed from the upstream and 

 downstream gravel removal areas, respectively. Access to the f I oodp I a i n was 

 gained via a gravel ramp which protected the floodplain incised bank. 



Prior to site abandonment in 1976, existing stockpiles and berms were 

 leveled and contoured, and the gravel fill ramp protecting the bank was to 

 be removed. Various aspects of this site are shown in Figures 44, 45, 76, 

 and 82. 



Ivishak River . The Ivishak River is a large, braided river which origi- 

 nates in the Philip Smith Mountains at an elevation of 1,829 m and flows 

 80 km through the mountains and 45 km through the foothills before entering 

 the Sagavan irktok River. The study site lies II km upstream from the conflu- 

 ence of the Sagavan irktok River. 



46 



