If you think that's nuts, I saw the same think in October next to the arena in my Ottawa neighbourhood.
I was walking back from work when I saw some guys snowboard and build a jump + table (included a picnic table from the park not yet removed for Winter). The snow from the arena was used on the steep hill next to the overpass (train).
The scene exactely like the pics except the hill was steeper and there wasn't any rail, only a pcinic table.