We would definitely recommend visiting Breckenridge. It is a beautiful mountain town 20 minutes south of Silverthorne. Walking around the town makes you feel like you're in Switzerland and the surrounding mountains are gorgeous. There is a free gondola that goes part ways up the mountain as well as a (not free) ski lift chair that goes higher up the mountain among many other things to do.
We would definitely recommend visiting Rocky Mountain National Park if you have time. It is 1.5 hours north of silverthorne.
If you want to do rafting while you're here, Clear Creek is probably the best option since its between Denver and Silverthorne. We have only been rafting at the Arkansas River which is a little further away, but Clear Creek has a good reputation as well.
There are so many different hikes to choose from, but below are a few of our favorites. The Enchanted Forest Trail in Apex Park is an easy-to-moderate 1.3 mile loop, featuring gentle climbs through dense pine forest and rocky outcrops just outside Golden. Mount Falcon Park near Morrison offers a moderate hike of about 4.7 miles round trip. This is where we got engaged. McCullough Gulch Trail near Breckenridge is a difficult, roughly 6.7-mile round-trip hike with a steep climb past alpine lakes and waterfalls. Be mindful of elevation as it reaches 12000 on this trail. This link provides different hikes in Silverthone!
Fireworks are banned in Summit County. Micah and Jordan will be going to the Breckenridge Drone Show and anyone else is welcome to join us that day. Text either Micah or Jordan if you would like to meet up for the drone show.