Craig Simson has been sailing on Dillon Reservoir since, as he puts it, “before I had a choice.” A native of Colorado, Simson comes from a sailing family and has had a boat at the marina for nearly three decades.

“This reservoir has always been a place that has been very meaningful to me,” he said. “It’s an amazing place of solace where people can come and look at one of the best views in Colorado.”

That was never the engineers’ intention. Rather, Dillon Valley was seen as a solution to Denver’s water problem. Front Range officials started eyeing the area as early as 1900 as the South Platte River could no longer serve Denver’s population and all the water rights claims on its flows.

“Dillon Valley did not have the minerals or the gold in Breck, the silver in Montezuma or mixed metals in Frisco. But it was centrally located at the convergence of the Snake River, Blue River and Tenmile Creek,” explained Sally Queen, Summit Historical Society’s board president.

In the early 20th century, Dillon was where stores could be found and where families settled. By 1910, the one-room schoolhouse had to be upgraded into a two-story building to accommodate the growing population.

Then the reservoir upended residents’ lives.

The Harold D. Roberts Tunnel, which shuttles water under the Continental Divide and is the longest of its kind in the world, broke ground in 1956. The Dillon Reservoir was completed in 1963. (Breckenridge Ski Resort opened in the interim, in December 1961.)

“It (Dillon Reservoir) came out of drought and need because the East Slope water supplies were not enough to meet the needs of the Front Range,” said Nathan Elder, water supply manager for Denver Water, which owns the reservoir.

The site’s origin story quickly became part of state lore: the entire town of Dillon, including the cemetery, had to be moved in order to make room for the dam responsible for sending the water toward the Roberts Tunnel. (So, no, there are no buildings drowned beneath the lake. Anything that wasn’t moved was burned.)

Though many residents were irate, it wasn’t a new reality for the hamlet. Dillon had moved locations three times before as railway lines shifted.

“People were still angry until about 2010 — the old-timers. They kept talking about the new town of Dillon,” Queen said. “The lake changed everything.”

Today, that 257,304-acre-foot lake is Denver Water’s largest reservoir. It serves as a supplemental supply for the utility’s 1.5 million customers and holds about 38% of its total storage water.

The reservoir — situated at 9,017 feet — has grown into a hot spot for outdoor enthusiasts, hosting one of the state’s largest sailing communities as well as boaters, stand-up paddleboarders, anglers, kayakers and others seeking either adventure or relaxation. Miles of paved hiking and biking trails, campgrounds and, in the winter, a cross-country trail system are all part of the recreation scene too.

“It can be a pretty complicated reservoir to operate, and that probably wasn’t envisioned when it was built,” Elder said.

A cooperative agreement signed in 2013 sets a goal for Denver Water to maintain a specific elevation for the reservoir, one that allows the marinas to be fully operational from mid-June through Labor Day while also protecting the surrounding area and the water-use needs to the east.

The utility also works with rafting outfitters to try and maintain enjoyable river flows throughout the season and with anglers to manage water temperatures for recreation and for the health of the fisheries.

“Lake Dillon is probably one of the best gems that we have here in Summit County,” Nina Waters, a county commissioner, said. “It’s a really valuable, vital income resource.”

That only grew more valuable as use swelled during the pandemic, similar to many outdoor locales.

According to the Dillon Reservoir Recreation Committee, an interagency group that manages the lake and surrounding properties, revenues have been growing by 5% to 7% each year. That translates to a $6.5 million economic impact on Summit County annually, Waters said.

Those numbers continue to evolve alongside the reservoir.

Dillon Amphitheater, which sits alongside the lake’s northern curve, was upgraded in 2018. The 2024 calendar is full of popular acts such as Maren Morris, Shakey Graves and Trampled by Turtles, and the shows regularly sell out. (There’s also a lineup of free performances throughout the summer.)

Currently, there is only a single restaurant serving all of the reservoir’s visitors: Pug Ryan’s Lakeside Tiki Bar. That could change in the coming years. “Both Dillon and Frisco are looking at potentially adding restaurants and other amenities to the lake as the interest increases,” Waters said.

Simson, who is now the director of the Dillon Marina, has had a front row seat to an “exponential” rise in popularity of water sports and use of the lake in recent years. But he says that growth hasn’t really changed the experience of being on the water. Sailors are still challenged by afternoon squalls and the surrounding topography. And the nearly 27-mile shoreline provides ample space for everyone to have a private experience, even on the busiest days.

“The opportunity to have water of this size at this elevation I think is really rare,” Simson said. “It’s 3,000 acres of water sitting between the Continental Divide and the Tenmile and Gore ranges. That really doesn’t change.”