groomed trail
what does grooming mean? well, first of all, in the Washington state Cascade range, a lot of snow falls... and if the temperature is in the twenties or lower, it'll be powdery... deep powder and if you try to walk in it, you'll be attempting to wade in it waist deep or deeper... not fun... so, you put on cross country skis... not fun either because now, you are spreading your weight across more surface but still sinking in quite deep... so you opt for snowshoes... if they are very large, like mine 10" wide and 36" long, you might be able to walk across the top of the snow sinking in a foot or so but still being able to locomote up the trail... With my weight, and with a pack, I need the large snowshoes for any snow conditions... (I just remembered that I was going to tell about grooming)... grooming means using a tracked machine like the snowcats (pictures soon) or a snowmobile which can move through deep snow... (if the fresh snow is deep enough the snowmobiles will just get buried) The vehicles weight consolidates (smashes the snow down a bit) and then the groomer dragged behind smooths out the surface so it looks like corduroy. It gives a very good surface for skiing with cross country skis and an easier surface to walk on with snow shoes. Walking without long or wide boards on your feet still is difficult depending on how consolidated the snow is. Here's a photo of the trail just after being groomed... you can see that the snow hasn't been compressed much so it is still about three to four feet deep. 
Peace
Peace