My family and I go to Boyne Falls, Michigan to visit the Mountain Grand Lodge and Spa about four times a year. In the winter you can ski or tube. In the Spring and Summer you can mountain bike, hike, golf, play tennis and in the fall you can do the same AND view the beautiful colors that come with the season! If you would like to get more relaxation after you visit the year round outside pool and hot tub (which are always nice and warm) you can visit the Solace Spa. For a daily fee you get a locker, spa robe, sandals, inside hot tub, eucalyptus steam room, dry sauna, showers and all the amentities you need to get read for the day - including razors, shaving cream, hair products, brush, and even q-tips!
If you need a little more excitement you can also visit Avalanche Bay! It is a great indoor waterpark for all ages! I also almost forgot to mention the beach with free putt putt golfing in the summer!