The back valleys behind Chase, Sorrento, and Tappen are ideal for mountain biking on quiet backroads. There are 3 potential roads/starting points, but we chose to start at the west end near where the Chase Creek Road meets the Turtle Valley Road. We rode west to Turtle Valley, turned left to create a loop route and then turned down the Skimikin Road past Philips Lake (almost to smaller Fleming Lake), then turned around and rode back to our parked truck, a total of about 30km.
There are some hills, but they are all gradual and not very long. These are good dirt-gravel roads that have been graded. Farmlands, forest, wet areas, small lakes, and rural homes are passed along the route. We rode for about 2.5 hours, but could have easily adjusted our turn-around point for more or less mileage.
There was a number of old buildings along the route, including the Turtle Valley School. Homesteaders settled in these valleys in the late 1800's. Farther down the Skimikin Road, we saw the donkeys at the Turtle Valley Donkey Refuge (link). Dark hills flank the valley on the north side. Ranches seemed to have more horses than cattle. The three lakes apparently have turtles, but access is limited by private property and fences. We were content to ride our bikes and enjoy the scenery.