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23 Cations of calcium (Ca), magnesium (Mq), and sodium (Na), which are utilized in calculating the sodium absorption ratio (S.A.R.), were scmewhat higher in the control soil than at other locations (Table 5). In many cases, all three of these cations increased between 1976 and 1979, but then decreased again in 1985. Sore of these differences may be related to a change in laboratories between 1979 and 1985. The zinc (Zn) cation was significantly higher in the control soil and did not vary greatly at any location t~etween 1976 and 1985. No differences in irrn (Fe) concentrations atmaig the six locations were noted, but minor variations in concentrations between the three times of sailing were detected at five locations. Lower values in 1985 may be related to the change in laboratories between 1979 and 1985. Manganese (Mn) levels were highest at location 3 and the control (No. 6), and lowest at locations 2 and 5. Again, lower levels of Mn in 1985 than in previous years may reflect differences in laboratory procedures between the two labs, as all sales collected in 1985 were analyzed by the CSU Soil Testing Lab but samples collected in 1976 and 1979 were analyzed by the Front Range Lab. The heavy metals molybdenum (Mo), cadmium (Cd), and lead (pb) showed varying trends (Table 5). Molybdenum concentrations in soils were higher in 1979 than in 1976 at all sampling locations. Ha+ever, this trend was reversed in 1985. Concentrations of cadmitan were near the detection limit of instruments, so no discernible trend among locations or years could b.: made. Lead concentrations did not vary greatly between 1976 and 1985. There was also no pattern in concentrations of lead among the six locations wit}1 respect to distance or direction from the mill. It, therefore, appears that molybdenum may be the only heavy metal analyzed for that may have increased