Alaska
Since 2006 I have been visiting a different place in Alaska each year, and hope to continue doing so.
2006: Wrangel/St Elias NP, Seward, and Valdez
2007: Homer and Kachemak Bay State Park
The Rails-to-Trails trail that starts where the Deschutes River joins the Columbia is a good route for mountain biking. It's well over 30 miles up. On this trip I went a bit over 12 miles. It was mid-January, and I didn't see anybody. The last two pictures are from a February dayhike in 2010.