The new 180-foot-tall, 1,285-foot-long Yellowstone Bridge is slated to open in 2025

The National Park Service had high hopes for a replacement for the Yellowstone River Bridge. As the park prepares to close most of its roads for the winter season, an important milestone is being reached.

Huge steel girders that will support the flow of tourists across the Yellowstone River are being installed throughout the 1,285-foot span. This brings the project closer to the November 2026 target, but traffic on the bridge will begin earlier.

“All the steel girders are in place,” Daniel Rhoades, a landscape architect for facilities management and operations at Yellowstone, told the Cowboy State Daily. “Weather permitting, we hope to have everything ready by Thanksgiving.”

New heights

The $118 million project to replace the bridge over the Yellowstone River is set to begin in 2023. The new bridge will replace the existing one, which was built in 1961 and is showing signs of aging.

Rhodes said this is the largest project he has been involved with in Yellowstone.

“The Pelican Creek Viaduct, which we completed in 2020, is 1,500 feet long, but only 17 feet high,” he said. “The existing bridge over the Yellowstone River is 604 feet long, while the new bridge is 1,285 feet long and 180 feet above the river.”

This makes the new bridge comparable to the Gardiner River Bridge at the North Entrance, which is 962 feet long and stands 201 feet above the river.

Yellowstone has not implemented projects at these elevations since the 1930s, when the Gardner River Bridge was built. Rhodes said making the new bridge much higher is an easier, safer and less intrusive option for the critical road corridor.

“The piers allow the bridge deck to reach the top of the Yellowstone River Canyon,” he said. “This minimized the excavation we had to do on both sides of the bridge. The old bridge falls down a steep slope on both approaches. The new design was created to maintain the level of grades.’

The towering concrete pillars went up over the summer using cranes you’d expect to see building skyscrapers in New York or Denver. A bird’s-eye view of the construction site shows a much smoother movement through the expanse of the Yellowstone River Canyon.

Delivery of steel

Now that the three concrete piers have reached the required height of 160 feet, the massive steel beams are placed on them. Rhoades said the beams are 9 to 15 feet high and 100 feet long.

“They are huge,” he said. “The steel beams go over the concrete piers, and then the concrete deck that the roadway will be built on will go over the beams.”

The logistics of delivering the beams to the construction site were difficult. Rhodes said the route through the park needs to be carefully planned to ensure the steel beams can be moved safely without damaging any infrastructure.

“They came in through the West Entrance and then through the Dunraven Pass,” he said. “A couple of bridges north of Madison Junction wouldn’t hold the weight, so we moved them up and over Dunraven.”

The transport of the beams from West Yellowstone to the construction site at Tower Junction was scheduled during off-peak hours, usually early morning, to reduce traffic impacts. Trucks with 100-foot beams had to be carefully escorted through narrow, winding roads to reach their destination.

“It’s a real orchestra that we’re coordinating,” Rhodes said. “The park, the contractor and engineers from the Federal Highway Administration worked together to determine the load figures for the bridge and developed a predetermined route. And they all did it.”

Higher compromise

Rhodes believes the new bridge over the Yellowstone River will be a “huge improvement” over the existing bridge. But as with every major park project, there were some compromises that would change the experience of crossing the Yellowstone River.

“It’s a constant battle for safety versus what the public wants to see,” he said. “But what the public wants should always be considered.”

One significant difference between the two bridges is that the existing bridge is much closer to the river. The new bridge will be much higher, making the river and canyon appear more distant.

Rhodes said safety and reducing the bridge’s impact on the landscape were priorities during the design, making the taller bridge preferable to the existing one. However, the new bridge was designed to offer a similar experience for visitors and local wildlife.

Rhodes said the Yellowstone River Picnic Area is being expanded as part of the project. The Yellowstone River Canyon Trail will be installed, offering “great views” of the river and canyon, as well as walkways on the bridge itself.

“There will be parking on both sides of the bridge and people will be able to walk on the deck if they want to,” he said. “There will be protective barriers between the road and walkways to ensure maximum safety for people as they cross the deck.”

These protective barriers will be a welcome addition to bison. The bridge over the Yellowstone River is a popular migration corridor for Yellowstone bison, as they reminded the builders many times.

“We had to slow down a lot because of the bison on the bridge deck,” he said. “The old bridge is a great bison corridor, and we expect that to continue with the new bridge.”

A whole year is another century

The road between the North and Northeast Entrances is the only road in Yellowstone that is open and serviced year-round, which was an important factor in the design and construction of the new Yellowstone River Bridge.

“Bridge engineers at the Federal Highway Administration say their structures are designed to last 75 to 100 years under normal wear and tear,” he said. “Every bridge has a lot of redesign for safety reasons, but this bridge is currently estimated to last at least that long.

This will be important when the new bridge opens to traffic. It will maintain a steady flow of traffic through the vital line for the communities of Cook City and Silvergate during the busy winter seasons.

In addition to the new parking spaces, a new interchange is also under construction across from Roosevelt Corrals. It will be slightly closer to Tower Junction and connect to the existing north-east access road to facilitate access and maintenance.

“Everything was considered,” Rhodes said. “This road is open 12 months of the year, so the height of the bridge maintains a level grade for safer winter travel.”

Opening of the bridge and Lost Creek

The “big push” to complete the new Yellowstone River Bridge will begin next spring. Rhodes said the precast deck panel will be placed on top of the steel girders, which will be covered with another layer of concrete to complete the bridge deck.

If all goes according to schedule, Rhodes hopes to start traffic on the bridge by the end of 2025. The only unfinished business will be the dismantling of the existing bridge, which will be completed by November 2026.

“We have to dismantle the old bridge and all the existing roadway connected to it,” he said. “We’ll start at one end and cut it into manageable pieces, and the pier will be demolished last.”

Dismantling the bridge of 1939 will allow important reclamation of the landscape. Rhoads said the final aspect of the $118 million project will be to rehabilitate the Lost Creek drainage.

“The Lost Creek drainage was damaged when the original road went through and we’re going to restore it to its natural function,” he said. “This will be an important part of the recovery as we bring out the previous road corridor.”

On the other hand

The Yellowstone River Bridge project is one of the most expensive construction projects in Yellowstone’s history. However, it already looks overshadowed and wasted by what Rhodes sees further down the road.

“We are now designing a permanent Mammoth-Gardiner road,” he said. “It seems to be a little more than this project. The Yellowstone River Bridge is the most expensive project to date, but I think the new permanent Mammoth-Gardiner Road will eclipse that one.”

Fortunately, funding will be made available through the passage of the Great American Outdoors Act. The act, which earmarked funding for the National Park Service, funded the construction of the Yellowstone River Bridge and will help cover the cost of the Mammoth-Gardiner Road once construction begins.

“We couldn’t have done it without the funding we received,” Rhodes said. “It comes from different sources for each project, and sometimes it’s a combination of funding sources. This is exciting work and we are very fortunate to be able to fund these great projects in Yellowstone.”

Andrew Rossi can be reached at the address [email protected].