We describe the design of a ground based telescope which would be sensitive to extraterrestrial gamma rays with energies from 10 GeV to over 1000 GeV. Among other things, this telescope would enable the study of the emission mechanism of gamma rays from active galactic nuclei (AGNs), and of the interactions of gamma rays from AGNs with the intergalactic infrared radiation field (IIRF), possibly permitting an improved measurement of the Hubble constant. Calculations are presented which show that with the energy sensitivity and aperture of the telescope, as many as a thousand new sources of high energy gamma rays from outside of our Galaxy could be identified, about 10 of which would each be capable of measuring the Hubble constant to within 10% (assuming the parameters of the IIRF to be known).
