Located at the northern tip of the Sonoran Desert, with scorching mid-summer temperatures, the rugged bench was thought to be good for little more than growing scrub and grazing cattle in the early 1900s. When partners Harry McWatters and Bob Wareham — then-owners of Sumac Ridge Estate Winery in Summerland — purchased a fallow vineyard site on the bench in 1992, intending to plant grafted vinifera vines imported from France, they raised more than a few eyebrows. Many thought it would be an expensive mistake.