Imagine it’s summer, 1928, and you are a college-age woman riding in the Cicada, an open-air bus converted from a Model T Ford that your teacher designed and built at El Sibil, his Oak Cliff studio.

You’re riding this jalopy out to West Texas with five other art students, who are male and female, along with a chaperone and your teacher, a bona fide impressionist master named Frank Reaugh.

For a month, you will paint the ever-changing Texas landscape en plein air every day beginning at dawn, producing Reaugh’s required minimum of four sketches. You take breaks in the heat of the day to swim in the creek, cook and have meals by campfire.

You are probably painting with Reaugh’s own brand of pastel paints, colors he designed to better capture the elusive subtleties of Texas skies and longhorn cattle. You could be sitting at the lap easel the painter invented for this style of work. At night you sleep under a canvas tent and perhaps dream of the four sketches you’ll produce the next day, and the next, and the next…

This was the experience for some lucky Dallasites during the four decades that Frank Reaugh studied West Texas with his students, capturing a cattle-grazing landscape that he knew was endangered.

A feature-length documentary, “Frank Reaugh: Pastel Poet of the Texas Plains” airs on TV for the first time in September. The film shows at 10 p.m. Thursday, Sept. 6 on KERA as part of “Frame of Mind,” a series devoted to independent film from Texas.

Set your DVR.