He made excellent wines and entered two vintages in the 1899 Paris Exposition winning gold and bronze medals for a claret and a Blanco, respectively.

Zinfandel and Cabernet Sauvignon became the dominant grape variety which was no surprise to those who knew the literature of California wine history three quarters of a century earlier.

Bottled Zinfandel under the Howell Mountain designation was a symbolic reunion of the ties established by the 1900 Paris victories by the Keyes winery.

The vineyards in Howell Mountain are planted between 1,400 and 2,200 ft (430–670 m) elevations well above the fog level in Napa Valley that are most affected by the cool fog and winds from San Pablo Bay while Howell Mountain, at the same time, is exposed to sunlight receiving larger amounts of solar radiation.

The mountain does get cool breezes directly from the Pacific Ocean, and the relatively high elevations result in a cooler climate than on the valley floor.