The Highwood Bench south of Fort Benton was one of the first 

 areas in Montana to be affected. Salt accumulation there has become 

 increasingly serious, with 10,000 to 12,000 acres of nonirrigated 

 farmland put out of production during the past eight years. It was 

 not until 1968-69, however, that an organized plan of action was 

 initiated by several farmers on the bench. The Highwood Alkali 

 Control Association (HACA) was formed in 1969 with 75 members. 

 At the association's behest, the Montana Bureau of Mines and Geology 

 (MBMG), Montana State University (MSU), Agricultural Research 

 Service (ARS), and SCS have begun to investigate the problem. 



To quantify the rates of growth and areal extent of saline seeps 

 on the bench, aerial photographs of the Nine Mile watershed taken 

 over a 30-year period were used. Accumulated percentages of the 

 total land area in the watershed (19. 1 square miles) affected by saline 

 seeps are as follows: 



1941 0. 1 percent 



1951 0.4 percent 



1956 2. 2 percent 



1966 9. 1 percent 



1971 19. 4 percent 



