In My Favorite Room, a recurring decorating feature, an interior designer or architect singles out a historic room they admire, which we deconstruct and, with the design pro’s guidance, translate into advice on emulating the look.

WHEN LAND speculator John Lewis built Lake McDonald Lodge, in 1914, his goal was bold: Entice U.S. travelers liable to grand-tour through Europe to visit the American Northwest instead. In Glacier National Park, his chosen site, the spectacular Montana Rocky Mountains easily approximated the Alps. But Mr. Lewis’s hostelry also had to equal the luxe accommodations overseas. His formula: Mix the grandeur of a Swiss chalet with frontier rusticity, as illustrated by the hotel’s three-story open lobby (above).

This memorable space was singled out by Max Humphrey, a Portland, Ore., designer who’s carved out a similarly distinctive American style, showcased in his new book “Modern Americana” (Gibbs Smith). His nostalgia-tinged aesthetic integrates the classic Yankee vernacular—plaid, gingham, quilts—with reserve, and he argues that, despite its opulence, the famous lodge’s lobby also demonstrates restraint. Placing lots of log furniture in a room of tree columns and stick-style railings “can come off as matchy-matchy or Disneyland,” he said. Instead, the décor mixes a variety of styles from the same era, a classic decorating trick. The Mission sofas and tables, Craftsmen carpet and Art Deco clock all hail from the early 20th century. The symmetry of the furniture placement also elevates the space.

Mr. Humphrey warns anyone attempting the look at home to stop short of painting their walls orange. While the color appears subtle here, with the unstripped logs and warm wood creating a tone-on-tone effect, orange can jar if paired with highly contrasting color. He also cautions against overdoing rusticity. Instead of wall-to-wall logginess, consider combining rough-hewed furniture—say, the woven chairs here—with modern furniture, like a Saarinen tulip table. Below, more of why the lodge design succeeds so well, and what might work at home.

Stand in Contrast

The unexpected colors in the rug elevate the décor, said Mr. Humphrey, “and by elevated I mean ‘hard to pull off for your everyday weekend decorating warrior.’” He also appreciates the use of the firefly-like motif. “Bigger scale patterns look better on bigger scale applications,” he said. “The rug would look very busy with the busy sofa fabric, and you would get so much less of the pattern of the rug if it were on the sofa.” Nab this smaller antique version of the wool carpet, made in India for Gustav Stickley circa 1910. Drugget Rug, $3,200 for 108 inches by 75 inches, daltons.com