Purple-black watery clouds loom bottom-heavy with pigment over a shining white farmland roof. Under the dark sky the roof looks wet and reflective, but is in fact white only because it has been left unpainted. Far in the distance the dark-bottomed thundercloud dissolves into a slanted deluge, spreading and diluting its color over a suggestion of hilly fields. Foreground is provided with a few wide lines.

The painting is as sure and true and gestural as a Japanese sumi painting, a work completed quickly, brush sometimes loaded and wet, sometimes dry and making scratchy lines.

“That White Roof” is one of about 50 watercolor paintings now exhibited at the Pacific Grove Art Center in The Way of Water, an homage to seven decades of painting by Rollin Pickford.

“You used to see him out painting all the time,” a viewer commented at a display of photos of the artist along with his paint kit and sun hat. In fact, according to Melissa Pickford Smith, daughter of Rollin and organizer of the exhibition, Rollin painted every single day until he lost his sight recently. He is 94.

“Being an artist is like any other vocation; it demands discipline,” Rollin said in a telephone interview from his home in Fresno. “You just have to paint and paint and paint and don’t let anything impede you; everything will if you allow it.”

Rollin admits that family can get in the way of work. He included his family in his working life.

“I spent a lot of time with my children,” he says. “Working at home, I’d take them outdoors to paint, to play. As adults they have remarked how much time I spent with them.”

Pickford’s Pacific Grove exhibition is testimony to his children’s regard. A gorgeous 285-page 1998 color coffee table-sized book California Light, The Watercolors of Rollin Pickford, was organized by son Joel Pickford, with four essays and over 100 full page reproductions of painting of 60 years.

Rollin painted on location—he liked to kneel on the ground to see from a low angle the fields, canals, beaches, Victorian homes, orchards and crops he captured under always-active skies. He was dubbed “painter laureate of the San Joaquin Valley” because of his thousands of paintings of the vanishing rural world of Fresno, where he grew up.

He says that his “spiritual home” was in the Monterey Bay area, where he painted every summer since the late 1960s. “It was a very exciting place,” he says as his voice becomes brighter—I can hear him smile. “I think of it now, every grain of sand, every shell, the fog…so different from the San Joaquin Valley.”

The Way of the Water exhibits the artist’s central technique of letting the  water on the page flow naturally, carrying the pigment along, and his mastery of many styles: tight drybrush drawings of village streets; a furiously painted abstracted impression of the Santa Cruz Boardwalk alight with color under a fanciful sky; wet-painted persimmons blooming fuzzily and brilliantly on a calligraphic branch; lowering Paynes Gray-colored skies over an impressionistically-daubed wetland marsh.

“The thing you’re trying to achieve is the essense of the subject,” he says. “I use whatever technique gets to that.”

THE WAY OF THE WATER continues through Feb. 15 at Pacific Grove Art Center, 658 Lighthouse Ave., Pacific Grove. A screening of The Master of Light, a film about Rollin Pickford, takes place at 2pm on Jan. 21. 375-2208 or  pgartcenter.org