Reports the first air-shower event with primary energy estimated at ~10^20 eV (later revised to ~1.4x10^20 eV), observed 1962 at the Volcano Ranch array (19 plastic scintillator detectors, Albuquerque NM). Establishes that cosmic rays reach energies orders of magnitude above any human accelerator, decades before the LHC. relevance_note: earliest primary evidence that Earth’s atmosphere already absorbs collisions vastly exceeding LHC centre-of-mass energy.