The Drifter Detective series.
2/12/15 update: And STILL more white fluff ahead which makes my three-year-old pleased because her castle is becoming quite elaborate and now includes an opening at the top. She crawls up and sits on the snow-packed roof and surveys her vast kingdom which includes a nearby bird feeder and her grandpa plowing the road. And just checking Amazon all the Drifter Detective titles have been reorganized. I do like the new look. Hopefully it kicks the series in gear.