It was uphill on the way out, and then downhill on the way back. I got lots of good cardio - about 50 minutes' worth - and had a great time too. I only fell twice, going slowly, and it was no biggie. Snow is soft. I did use a lot of unfamiliar muscles; I can tell I'm going to be a bit sore tomorrow. Oh well...it was worth it! I really need to do this more often.
Garmin data here.