After the first of May the country dried brown, then yellow, then white. Everything became intensely dry under the continuous rays of the sun. Grass crackled under foot, twigs broke, boards split on slight provocation. In the open fire was thus a menace of the first magnitude. Every workman, every farm laborer was cautioned, was questioned as to whether he smoked or not. The danger was particularly great in days of north wind with its low humidity.
And then finally came fire on semi-quiet but soon stirring a wind in its wake, running rapidly over the grain fields and eating up the great stacks waiting
for the thresher, forming huge billows of black smoke, spreading in a great ominous arc that cut the sky from north to south, spreading everywhere a sense of terror, horror, despair. Blazing shoots of flames parted into longer and longer lines of glowing fingers scattered widely over the plain. Ruin, destruction, desolation, blackened fields and bits of charred fence lines lay in the wake of the fire.
The Vaca Mts. Burned over repeatedly. Regarding Indian fires in Sierras, see Univ. Cal. Publ. Archae. & Ethn. 31:363; a definite a remarkable statement about Indian practice.
Geology of the Potrero Hills and Vacaville region. T.L. Bailey (Univ. Cal., Publ. Geol. Vol. 19, no. 15).