The direct answer: the best pergola material for a Utah yard is the one sized, detailed, finished, and maintained for the site. Stillbury uses real Douglas fir as the natural starting point, then confirms finish direction and structural details around the design.
Utah sun, dry air, freeze-thaw cycles, and snow exposure make detailing matter. Footing planning, drainage, shade orientation, roof design, and finish maintenance are part of the material conversation.
Material choice should support the way the structure will be used: visual warmth, long spans, shade comfort, and a finished look that fits the home.