With a staggering 60% slant, Jackass Hill is the steepest non-terraced vineyard in Sonoma County and the most harrowing to harvest. Yet every year, Lee Martinelli teeters on his tractor trying to defy gravity on this daunting slope.

Before him, his father, Leno Martinelli, farmed it for 75 years, up until he was 87. And the original daredevil, Giuseppe Martinelli, farmed Jackass Hill with horses for more than 30 years, after planting its vineyard in 1889.