The average counselor salary at Prosser was $68,598 , which is 35 percent lower than the average salary for this job in Washington, and 9 percent lower than the national average for this job . Counselor salaries at Prosser typically range from $59,294 to $76,024 (25th to 75th percentile). The highest reported counselor salary was $92,069. There are 8 employees at Prosser with the job title counselor.