Results of theoretical studies of rotationally resolved photoelectron spectra for (2+1’) resonance enhanced multiphoton ionization (REMPI) of the C (2) Sigma(-), D (2) Sigma(-), E (2) Sigma(-), and F (2) Sigma(-) Rydberg states of ClO are presented. Cooper minima are predicted to occur in the electronic continua for photoionization of the D and F states and lead to unusual behavior in the ion rotational distributions. Strong partial wave I mixing is also predicted in the continua for the C and E states due to the nonspherical molecular ion potentials. These Cooper minima and I mixing make the associated photoionization dynamics quite nonatomiclike.