I've lived most of my life in the Sierra foothills - growing up in Sonora, moving to Penryn after college, and later moving to Auburn. The proximity to the mountains, the distinct seasons, the mix of snow and rain in the winter, the nice weather in the summer - these are some of the reasons I've chosen to stay in this region.
At the 80th birthday party of a friend who has been in Auburn most of his life, we were talking about what makes this part of the foothills so attractive. For me, a big reason to stay here (both as a farmer and as an eater) is our year-round farmer's market. We're incredibly fortunate to live in an area where it's so easy to get locally grown food 12 months out of the year.
My parents have now lived in Sonora for more than 40 years, and while they aren't quite "old timers" compared to the families who have been in Sonora for 4-5 generations, they've been there long enough to not be considered newcomers. Auburn has a more transitory feel - our proximity to Sacramento has created a lot more growth pressure than other foothill towns have experienced. This difference, at least to me, makes it seem like one can be an "old timer" sooner than in other places. I have also come to think that being an old timer is more a matter of perspective and less a matter of chronology.