We report a ZGP OPO/OPA system capable of producing >30 mJ at a signal wavelength of 3.4 μm. Our pump source for the OPO/OPA is a 2.05-μm, diffraction-limited Ho:YLF master-oscillator power-amplifier (MOPA) producing ~150 mJ energy per pulse at repetition rate from single shot to ~500 Hz (>100 mJ at 1 kHz). The Ho-MOPA output was split ~2:1 into two beams: one (~50 mJ per pulse) pumping an image-rotating RISTRA ZGP OPO to generate a 3.4-μm signal wave with >10 mJ of pulse energy and near diffraction-limited beam quality, and the other to pump a ZGP OPA stage to increase the signal wave to ~30 mJ per pulse.