Piper, Luna, and the Sled

It’s been a snowy few days here so of course Piper is in heaven.  The latest project involves tying Luna to the sled with her leash.  There is also a long line so Luna can’t get away.  I think the idea is to get Luna to pull the sled up the hill.  This seems to be only moderately successful, since I notice Piper expending quite a bit of energy running down the hill to get Luna to chase her up it.