I have walked up Hartz Mountain many times and in different conditions. Last week, after a heavy snowfall I thought I would gIve Hartz a visit. Got as far as the the first registration booth and I was literally bulldozing though snow in my Subara Forrester. I left the car, put on my snow gear and waded through waist deep snow along the track. I got as far as the falls side track before the snow got even deeper. I'm not overly tall but when the snow comes up to your chest it's prolbably time to turn back.
I looked across to where the track to to lakes and summit should be and, even though the snow looked even, I knew there was dip in the valley and snow must be even deeper.
Made it back to the car and it started to snow again. Couldn't turn the car around so reversed back down the mountain along the tracks I had come up by.
Best trip up Hartz ever.