Thank you all for your well thought out answers. As Alanabit noted, it is our subjective view on what makes a 'western'; I'm look forward to more opinions.

I think that all of the titles I mentioned this morning (actually last night on the sunset coast) are westerns. But for me the classic western setting would be the decades of the 1870s/80s, and the story would have many of the elements,in various combinations, noted above. It would be a moral tale of big/small, altruism/greed, good/evil....but it could also be a story about just overcoming the hardships of life in a rural setting.

I don't expect to find historic accuracy, necessarily; else why would we have umpteen versions of the OK Corral story, and why would Wyatt Earp be portrayed as a man in his 50s or 60s in 'Winchester '73', when he actually would have been about 35 years old then?