While vacationing at Keystone Mountain Resort, you need to make the most of all the fun summer activities available. The cool summer weather in Keystone is perfect for adventure sports. So you or your family will never be bored. Even when occasional cold snaps strike, there are plenty of indoor activities and entertainment options to choose from. Biking: Once you get to Keystone, you will notice that there are many bike paths everywhere. Infcat, there are over 100 miles of mountain biking trails in Keystone. You can take the paved Keystone to Breckenridge trail that circles Lake Dillon, or take the off-road trails that surround the Keystone Valley. During your stay, be sure to enjoy the thrills of downhill mountain biking. The gondolas run all summer, so take your bike to the top of the mountain and run all the way down. Hiking: Exploring the Keystone hiking trails can be very rewarding. Not only is it a fun activity, but you can also observe many wild animals without disturbing them. There are many trails you can hike on; Wheeler National ...