Evergreen Outdoor Center have some fantastic programs available during the long weekend October 6–8 and also the mid-term break, especially for families who want to get away and enjoy the autumnal colours of Hakuba.
Check out the half-day canoeing adventure and picnic. Just ¥20,000 for a family of four. Or a full-day combination of canyoning, mountain-biking, rafting, or climbing activities for ¥10,000 per person, including lunch.
Separate programs can be organized so that parents can have a little bit of time to themselves while the kids go on activities with qualified, experienced instructors.
See http://www.evergreen-hakuba.com/tours/combo-packages.html for more information.
