From the gate, follow the singletrack off to the left. It should make a turn up the hill, and start heading towards a big grassy field. Look towards your left in the bushes, and very quickly you should see a trail that drops into the trees there. Hit that! It is an amazing section of trail that swoops up and down in the gully. Afterwards, just keep following the singletrack. The singletrack will join the ski trail occaisionally, but there is a well-worn route to follow. Just keep following it, and follow any signage. There is a downhill-type trail that spurs off the furthest corner of the main cross country loop, if you wanna hit it.
So yeah, just follow the trail all the way around the mound, and you'll get back to the start. Sprinkled around on the trail there are a see-saw, some very fun bridges, and drops and jumps on the downhill section. Enjoy!
Coming from Wisconsin on 63, take a left at Potter St. and then a left on 7th St. Go until you see the massive sign for Memorial Park, and hang a right into it and start driving up the hill. Get up to the top of the hill, go around the one way, and keep bearing right. Start driving down a slight hill, and if you reach the turn around at the bottom, you've gone too far. Turn around and head up hill just a bit, and look for a gate on your left. I'd recommend parking in front of the gate, or parking at the turn around and riding up to here (now see description).
http://www.singletracks.com/item.php?c=1&i=2659