Headed over to Bend/Redmond in a few weeks and going to haul the kid and her XR50 over. Where would be a good place to take her where it won't be too rocky on those little wheels. Otherwise looking at hitting up as much as route 4 on the OBDR as I can. I am ok with starting in Sisters.
The only good part of route 4 is from Prineville east. Sisters - Prineville via route 4 is a few large gravel roads, then pavement. There is Cline Falls area, but I have not been there. The largest area being China hat SE of Bend.
There is a little play ORV area just east of LA Pines. It is pretty sandy, didn't see any rocks there. If you head SE out of Bend on China Hat road there are hundreds of miles of dirt side roads. Could be a little muddy and snowy still, though.
Probably the Millican valley area would be a good bet. There are many easy trails and a play area with a little loop that goes around it. I remember years ago riding a little Pw80 there with my arm in a cast.
Henderson Flats between Terrabone and Culver is a good one. Lots of easy stuff there. It's behind McPheeters turf and opens for riding April 1 Trail called learners loop is one way direction I believe. http://www.fs.usda.gov/wps/portal/f...tral+Oregon+-+Henderson+Flat+OHV+Trail+System