1960s in drug-use sense, from ozone (n.), which is found high in the atmosphere; the related verb to zone is from 1980s.
Entries linking to zoned
ozone n.
modified form of oxygen, 1840, from German Ozon, coined in 1840 by German chemist Christian Friedrich Schönbein (1799-1868) from Greek ozon, neuter present participle of ozein "to smell" (see odor). So called for its pungent odor. Related: Ozonic.