  We examine the effects of ionization, radiation pressure and main sequence
winds from massive stars on self-gravitating, clumpy molecular clouds, thereby
modeling the formation and pre-supernova feedback of massive star clusters. We
find the process of ``turbulent mass loading'' is effective in confining HII
regions. Extrapolating typical Galactic high-mass star forming regions to
greater initial gas cloud masses and assuming steady star formation rates, we
determine the timescales for cloud disruption. We find that a dense n_c ~ 2 x
10^5 cm^-3 cloud with initial mass M_c ~ 4 x 10^5 M_sun is able to form ~2 x
10^5 M_sun of stars (50% efficiency) before feedback disperses the gas after ~3
Myr. This mass and age are typical of young, optically visible super star
clusters (SSCs). The high efficiency permits the creation of a bound stellar
system.
