Five Mega-Projects That Promised Massive Change But Never Broke Ground

DENVER, CO – Denver’s skyline and urban landscape are constantly evolving, but not every bold announcement makes it from concept to construction. Over the last decade, several highly publicized projects generated buzz, renderings, and even approvals, only to stall or disappear. Some may still resurface, while others remain lessons in the challenges of development at scale.

Here’s a closer look at five of the biggest:

1. The 90-Story “Six Fifty 17” Tower

In 2017, Greenwich Realty unveiled plans for a 90-story skyscraper at 650 17th Street — a twisting, spiral-style design that would have dwarfed everything else in Denver. The project promised condos, hotel space, and luxury amenities, positioning it as a centerpiece of the city’s growing downtown.

But the hype never translated to reality.

• The land deal fell through: Greenwich’s contract to buy the parking lot at 650 17th Street expired in 2018. Without ownership of the site, the project was dead in the water.

• No permits were ever filed: Despite splashy renderings, the project never advanced beyond a preliminary application.

• Market doubts loomed: Analysts questioned whether Denver could sustain a project of such cost and scale, especially in a market dominated by rental demand rather than ultra-luxury condos.
  By 2019, Boston-based Harbinger Development had purchased the site and is now pursuing a smaller residential/hotel tower topping out at 39 stories.

2. Bell Park Residences & Office (36-Story Tower)

This prominent site at Speer and Market has been through nearly two decades of stalled visions. In 2019, Texas-based Kairoi Residential teamed with property owner Buzz Geller to propose a 36-story residential and office tower.

But by late 2023, the deal was officially terminated.

• Costs soared nearly 40%, making the project financially unfeasible.

• Design reviews dragged on for years, as LoDo’s design commission repeatedly rejected earlier versions.

• The site itself is tricky, with zoning restrictions, a view-plane corridor, and a small buildable footprint.
  Bell Park’s saga actually stretches back to 2008, when a 34-story condo tower died during the Great Recession. Multiple attempts since, including a hotel/office hybrid, have all failed to stick. Today, the site remains a parking lot.

3. Spaceport Colorado at Front Range Airport

When the FAA granted Adams County a license in 2018 for a horizontal-launch spaceport at the former Front Range Airport, officials envisioned a new hub for suborbital aerospace launches. The branding was bold: Colorado could be at the forefront of commercial space travel.

The reality has been far more limited.

• Horizontal-only launches and proximity to DIA restricted operations.

• No vertical rockets meant less appeal compared to competitors like Spaceport America in New Mexico.

• Funding never materialized, as the FAA doesn’t provide direct spaceport development money.

Instead, the Colorado Air and Space Port evolved into a research hub. It has since attracted companies like Boom Supersonic and Reaction Engines for engine testing, but the vision of frequent space flights never left the ground.

4. The River Mile

Announced in 2018 as a $6 billion, 25-year redevelopment of the Elitch Gardens site, The River Mile promised 15 million square feet of mixed-use development along the South Platte River: thousands of housing units, office towers, retail, hotels, and public space.

Progress, however, has been slow.

• Rezonings were approved, but site work largely stalled after initial marketing pushes.

• Ownership shifted in 2025, when Kroenke Sports & Entertainment (KSE) bought out Revesco Properties’ stake, giving KSE full control of the 62-acre site.

• Integration with the Ball Arena campus suggests a new long-term “Sports Mile” vision, but concrete next steps remain unclear.

For now, Elitch Gardens and Meow Wolf remain open on the site, while the massive redevelopment remains a future ambition under KSE’s broader portfolio.

5. DIA “Plan 100” / 2045 Expansion Concepts

DIA’s Master Plan, dubbed Operation 2045, laid out an ambitious goal: accommodate 120 million annual passengers by the airport’s 50th anniversary. Concepts showed an expansion of the Jeppesen Terminal, four new concourses, and nearly 100 new gates, essentially doubling the airport’s footprint.

While the plan remains technically “active,” most of the bold renderings have taken a back seat to immediate projects like the Great Hall remodel and new concourse extensions. DIA’s Vision 100 program is working toward 100 million annual passengers, but the broader $12+ billion 2045 vision remains a long-term, constantly evolving roadmap, not a construction project happening anytime soon.

The Takeaway

Big ideas drive Denver’s growth story but not all of them materialize. Some projects, like the River Mile, may still resurface under new leadership. Others, like Six Fifty 17 or Bell Park, serve as reminders of how volatile financing, design approvals, and market conditions can be.

Stay tuned as Developing Denver continues to track the bold proposals, the stalled plans, and the projects that ultimately do reshape the city’s future.

All project information was sourced from publicly available site plans, renderings, and permitting documents.

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All project information was sourced from publicly available site plans, renderings, and permitting documents.