Lago Argentino (Argentina) — March 18, 1950 (1830)
A rancher, Wilfredo H. Arevalo, saw two objects, one of which landed. He walked within 150 m of the aluminum-looking craft, which gave off a grccnish-blue vapor and “an intense smell of burning benzine.” A large, flat section on top was revolving above a glass cabin in which could be seen four tall men, dressed in something like cellophane, working at various instruments. They saw him and shone a light in his direction while a blue light illuminated the craft; the vapor increased and flames (alternately reddish and greenish) shot out of the base while the object rose with a faint hum. Both craft flew away toward Chile, leaving bluish trails. (Humanoids 32)
Source: Passport to Magonia
Case: 73