The trails at Mariton are snow covered, but great walking. There is a slight crust because the last snowfall ended as freezing rain. You can break through the crust easily for traction. It probably isn't deep enough for skiing.
The parking lot is clear and dry. Sunnyside Road is also pretty good. So, access to Mariton's trails isn't an issue.
Bluebirds have been seen feeding periodically in the Eastern Redcedar in front of the Nature Center. Bluebirds and Robins enjoy the berries on the tree. Other birds also like the berries including (obviously) Cedar Waxwings. Pileated Woodpeckers are still active on the eastern side of the Sanctuary. Bald Eagles are occasionally seen from either the River Lookout or the Chimney Rock. There are lots of tracks to examine. You can easily find Red Fox and deer tracks, but you should also be able to find the tracks of squirrels, racoons and turkeys.