Dillon Reservoir is Summit County's summer centerpiece, a sparkling expanse of water set like a sapphire in a cradle of gleaming peaks. Kayaks and sailboats ply the water, anglers line the shore and cyclists pedal around the edge on the local bike path. If you look closely, you might even spot the area's newest residents — a pair of bald eagles nesting on island between the towns of Frisco and Dillon.
But Dillon Reservoir is much more than a place to play. It's the key piece of an extensive plumbing system that reroutes vast amounts of Colorado River water to the other side of the Rocky Mountains, where it has fueled growth, enabling the Denver area to become one of the great metropolitan centers of the modern West.
Before Dillon Dam was built in the early 1960s, visitors would have seen a broad valley, scored by several canyons and marked by a stunning confluence of three rivers: The Blue, flowing down from Breckenridge, the Snake, draining the area around Keystone and Tenmile Creek, gathering waters from the west all the way up to Vail Pass.
The valley was probably a gathering spot for Native Americans long before the first fur traders and gold seekers came to the area in the early 1800s, but it didn't really rate on many maps until 1883, when the town of Dillon was incorporated at the site of a trading post and stage coach stop. Little did those early residents know that their entire town, including the cemetery, would one day have to be relocated when Denver Water developed the area for water storage.
Along with the entire town of Dillon, 13 miles of highway, eight miles of transmission lines, a hydroelectric generating plant and a forest ranger station had to be relocated. The reservoir nearly doubled Denver’s existing raw water storage facilities, and ranks as one of Colorado’s largest bodies of water.
So how do you move millions of gallons of water from one side of the Rockies to the other? With a tunnel, of course. In what was, for its time, a challenging project, crews spent 16 years drilling and blasting the 24.4-mile Harold D. Roberts Tunnel, which is nearly the same length as the Chunnel under the English Channel. The reservoir and the tunnel literally reroute a big portion of the Upper Colorado River's flows into the South Platte River Basin.
That's enough history for now; it's time to get out and enjoy the reservoir! There may have been some bad blood between high country residents and Denver back in the early days, the two sides now work cooperatively to manage the reservoir and surrounding lands for everyone's benefit.
Here are some of our favorite spots around the Reservoir:
- A great example is the Dillon Nature Preserve, located just off the west side of Highway 6 between Dillon and Keystone. The preserve is one of Summit County's best-kept secrets. A pair of gentle hiking trails wind through sagebrush and wildflower meadows, as well as a diverse forest that probably comes close to approximating what the landscape must have looked like before Dillon Dam was built. The nature preserve is located on the peninsula where Denver Water operates the intake for the Roberts Tunnel.
- Sapphire Point, off Swan Mountain Road, is a much more popular spot — to the point that many people actually get married there, but it's still well-worth a stop because it offers stunning panoramas of the entire reservoir, especially since mountain pine beetles attacked and the Forest Service subsequently cleared parts of the forest in the area. The rocky outcrop is also a great spot for kids to get up close with hungry chipmunks and birds. While wildlife experts always recommend against feeding wild critters, it seems to be tolerated here at Sapphire Point, so be sure to bring some sunflower seeds! Also, be sure to look for some unusual evergreens with small, spiky cones. The giant Douglas firs growing here are probably some of the oldest trees in Summit County.
- Some of the best hiking and mountain bike trails around the reservoir are on the Frisco Peninsula, located between Frisco and Breckenridge on the east side of Highway 9. The Frisco Nordic Center also maintains crosscountry ski trails here in the winter. The peninsula juts way out into the reservoirs with great views of Dillon Dam on the other side. One of our favorite trails goes all the way around the edge of the Peninsula, starting at the Dickey trailhead, near Farmers Korner and ending at the Pine Cove day use area, near the Forest Service Pine Cove campground. The peninsula is also a great place to see how Summit County forests have been treated in the wake of the pine beetle outbreak, and how the lodgepole pine forests are growing back. Check with the U.S. Forest Service Dillon Ranger District for more information on trails. After your hike or bike ride, be sure to stop in at the Frisco Marina Tiki Bar for a cold beverage and tasty snacks on a deck looking out over the fleet of local sailboats.
- Near Frisco, along Dillon Dam Road, the Giberson Bay day use area beckons with trails that run right along the water's edge, perfect for picnics and bird watching. Be sure to bring binoculars because this year, a pair of bald eagles has established a nest on one of the islands near Heaton Bay. The official day use parking area costs $5, but there are several turnouts along the Dillon Dam Road where you can park for free and access the same trails. When the reservoir level is high enough, this area also offers wheelchair fishing access.
- Finally, for a more developed waterside experience, visit Dillon's Marina Park, where there's a network of paved walking paths leading through a cute statue garden with historical information about the area, picnic tables and grills and great playground for the little ones. The amphitheater offers ongoing concert and theater performances during the summer, and the nearby Tiki Bar at the Dillon Marina is the perfect spot for refreshments.