The Rainbow Boys(1973)

Struggling to subsist on negligible and infrequent gold discoveries, prospector Ralph Logan crosses paths with Mazella, a New York City drifter with a three-wheel motorcycle and plenty of time on his hands. After introducing his new acquaintance to the practical but volatile Gladys, Logan suggests the trio join forces for a mission deep into the mountains of British Columbia in search of his father's elusive stash of gold.