Why we shouldn't dismiss Cather as just a regional writer

Willa Cather's 1917 novel, O Pioneers!, is great in surprising ways.  When you start the novel you think you'll be reading a paean to the harsh beauty of the Nebraska prairie and of the tough life of persistence, ingenuity, and perseverance that marked the pioneer spirit - even in the late 19th century. Yes all that's in this novel esp in the first section, which begins w a description of a small prairie town in mid-winter.  But as we move into the 2nd (of 5) and the longest section, circa 1900, the novel begins to take shape as a complex family drama, maybe even melodrama - Alexandra the unmarried oldest sibling in the Bergson family runs the family farm thru her wit and common sense and makes the prescient decision to invest in more land even when times are hard. Her two adult brothers are each shifty in different ways, one just a big strong slug w no common sense the other a sly budding Midwest politician. Neither could possibly run the homestead on his own. Then there's the younger children now about 18 or so in this section, yearning for a life of their own in a big city, maybe in the east. And there's the one who got away, the you man who seems to be the obvious love interest for Alexandra - he went away to the city and now is returned for a visit and he's not what we would have expected. In a bad novel he'd be a romantic hero who would spur a passion in the isolated Alexandra - think bridges of Madison county - but in this novel has a sad washed out disappointment , heading on a foolish venture to the Alaskan gold fields. And then there's the next neighbor. "Bohemian" - i.e. Czech, farmer clearly a mismatch w his high-spirited young wife. In short there's a lot of tension, simmering sexuality yearning, and disillusion in this seemingly placid, romantic novel.  Cather is ever sly providing much more then we expect - it's too easy to dismiss her as a regional writer she's much more.