  We will use immersed surfaces to study Seifert fibered surgery on Montesinos
knots, and show that if $\frac 1{q_1-1} + \frac 1{q_2-1} + \frac 1{q_3-1} \leq
1$ then a Montesinos knot $K(\frac{p_1}{q_1}, \frac{p_2}{q_2},
\frac{p_3}{q_3})$ admits no atoroidal Seifert fibered surgery.
