A wood fence in Phelan or Oak Hills lives a harder life than the same fence in a coastal suburb. Summer UV dries and checks the boards, winter freeze-thaw works on the post footings, and the wind that funnels through the Cajon Pass leans on every panel. None of that is a reason to skip wood. It's a reason to install and care for it properly.
Start with the install. Posts should be pressure-treated, set in concrete, and deeper than the bare minimum for the fence height. Six-foot privacy fences want three rails, not two, so the pickets don't cup and the panel doesn't rack in a gust. Leave a small gap at the bottom so the boards aren't wicking moisture from wet soil or sprinkler overspray.
Then seal it. A penetrating stain or clear sealer applied within the first few months, and again every two to three years, is the single biggest thing you can do to keep a wood fence from going gray and brittle. Pick a product with UV blockers, spray or roll it on a calm morning, and hit the end grain on the tops of the pickets, which is where water gets in.
Finally, walk the line once a year. Tighten loose screws, replace any picket that has split, and check the gate hinges and latch. Fifteen minutes each spring keeps a small problem from becoming a leaning section, and it's the difference between a fence that lasts and one you're replacing in a decade.