Summer Park Activities:
Summer bus trips
Day hiking
backpacking
Mountaineering
Cycling
Fishing
Wildlife viewing
Winter Park Activities:
Cross country skiing
Snowshoeing
Snowmobiling
Winter camping
Star gazing
Flight seeing
Dog sledding
http://www.nps.gov/dena/planyourvisit/winter-activities.htm Check out some activities on the official national parks website!