I hit 6 Mile this morning. I rode the canal side of the park. I feel like I saw things a little differently than the guys writing the two previous posts. I would describe the trails as "rideable". I agree with the 4o% snow cover on the trails. The Blue trail coming out of the canal lot was a rutty, frozen mess coming through the field. Once in the woods the trails were hit or miss. The field runs on Blue were covered with lumpy, frozen snow which was slow going but not too bad. The White Trail coming was sketchy in a multiple spots. A very light covering of snow over ice made it very dicey for a 1/4 mile or so coming off the Red Trail through the cedars. Same thing for the 1/4 mile or so of the White Trail near the lot on Jacques Ln. The best section of trail by far was the Red Trail between Canal Rd and Rabbit Chase Run, very little snow cover and very smooth.
My two cents, take a ride to Hartshorne. I rode Harts and Huber woods yesterday and the trails were pristine. I rode 14 miles and saw one section of trail (maybe 100 or so ft) that had any snow, other than that the rest of the park was fast and smooth.