Highest Prosser employee salary in year 2017 was $159,727. Prosser employees number in year 2017 was 383. Prosser average salary was $46,626 and median salary was $41,741. According to the last payroll, Prosser average salary is 38 percent lower than USA average and 38 percent lower than Washington state average. Prosser employee salaries are usually between $20,879 and $70,069. Top 10% of highest-earning employees have salaries ranging from $81,217 to $159,727.