Bridging the Platte River

An early bridge near Kearney, Nebraska. Crossing the mile-wide historic Platte River was no easy task. (Photo Courtesy Nebraska State Historical Society)
Listen to this story: 

March 17, 2015 - 6:45am

Just south of Interstate 80, a little west of Kearney, semi trucks, trailers, and cars zip over the Elm Creek bridge on a January afternoon. Most drivers barely glance at the Platte River below.  Today we may think nothing of driving over a bridge. One hundred and fifty years ago, it wasn’t so easy.

The Platte River Valley is mostly flat, oriented east to west and adjacent to the Missouri. As a result, the “Great Platte River Road” became a major thoroughfare for explorers, settlers, and homestead traffic in the 1800s. Many goods and services first concentrated along the route of Union Pacific’s transcontinental railroad, north of the river.

“The area was being settled fairly quickly, and the river really was the key stopping point,” said Russ Czaplewski, a historian who spent many years working in Dawson County in central Nebraska.

“If the river was high the people on the north side couldn't travel with supplies from the small railroad towns that had been established to their farms on the south side,” Czaplewski said.

Early entrepreneurs were eager to connect the markets across the river. But in the era when people traveled by wagon, quicksand and periodic floods made crossing the wide, flat river often impossible. Without much local timber available, some of the earliest Platte bridges were made from sod.

“Now the actual fun of crossing such a structure with the river under you, I would think that was rather concerning,” Czaplewski said.

Early bridge builders were challenged by floods, ice jams, and the natural weather extremes of the central Plains. Sod or timber bridges were frequently destroyed and rebuilt several times. Finally, Plum Creek, now Lexington, built the first bridge across the Platte in 1873, and other towns quickly followed suit. One of those early sod bridges was south of the Cozad colony.

“It was continually dealing with issues of being washed out. It was just extraordinarily difficult,” Czaplewski said.

Some of the earliest bridges spanned the mile-wide girth of the historic Platte or its multiple broad channels. But early on bridge builders commonly built embankments out into the river to shorten the actual span of the bridge, to try to tame the river current and save on construction costs, Czaplewski said. As rail and road development continued to expand after the turn of the 20th century, bridge builders began using better construction techniques and materials like cement and steel.

(Courtesy Nebraska Department of Roads)

Construction of the Lexington Bridge in 1915. Early bridge builders were challenged by weather extremes and natural events like ice jams and spring floods.

But those stronger, narrower bridges had ecological impacts on the river’s flow, said Greg Wright, a biologist formerly with the Crane Trust, a conservation group active in the central Platte.

“By putting a structure in the river you change the river. The tendency is to want to constrict the river so that the bridge can be shorter,” Wright said. But those constriction points alter the flows and structure of the river channel.

It got even worse during the twentieth century, as bridge builders and riverside landowners constructed higher embankments or rocky levees to prevent flooding and bank erosion. These structures can further constrict flows and increase the speed of water going downstream.

“Essentially that started small-scale changes,” Wright said, that, coupled with the changes in water use from upstream dams and diversions,  “created the river that we see now.”

Comparing the historic, sweeping Platte River floodplain with today’s river, the bridges are “probably negative for wildlife,” Wright said. “Because each time the river tries to widen out and act like an actual river, it's able to do that for 10 miles then it's choked back down and then it has to start it again.”

The Federal Highway Administration created stricter regulations to start addressing these concerns in the 1980s.

“We typically think of about a quarter-mile upstream and downstream of the bridges as not being good for habitat for the species that we deal with,” said Jason Farnsworth of the Platte River Recovery Implementation Program, which aims to conserve and enhance habitat for four threatened or endangered species: whooping crane, piping plover, least tern and pallid sturgeon.

This story is part of a larger reporting project from Platte Basin Timelapse. Find more on this story and many others focused on the conservation history of the central Platte region starting March 18th on the PBT website.

Farnsworth said bridges can be challenging for river ecology and wildlife, and yet they have also played an important role in the restoration activities on the river in the past few decades. Bridges typically occur every 10 to 15 miles in the channel, functioning as a kind of mile-marker.

Conservation groups on the central Platte use the bridges as a handy way to split up segments of the river, often aiming to secure one piece of conservation land in each segment, said Farnsworth.

Standing by the Elm Creek Bridge near Kearney, Farnsworth said this bridge represents a good learning opportunity.

“The area downstream of the bridge is managed, so you can see all of the work that's been done to widen the channel and create habitat for these species,” Farnsworth said. That work includes mechanically removing plants and trees and recreating bare sandbars in the river.

“Upstream of the bridge has not been managed so you can kind of see what the river wants to look like in absence of our efforts to keep it wide and unvegetated,” he said.

The historical river was often a mile wide in the central Platte. Today’s river, with only a quarter of historical flows running through it, breaks up into smaller streams separated by large islands. So bridges can sometimes help certain wildlife species by concentrating the remaining water.

“Bridges actually give us a place where we can have that flow combined and a place to start from as we consolidate flow downstream,” Farnsworth said.

Ultimately, with nearly all the riverside property in private hands, today bridges offer one more important benefit: It’s one of the few opportunities Nebraskans have to actually see the Platte River, even if it’s from the window of a speeding car.

This story was produced by the Platte Basin Timelapse project, a long-form multimedia documentary project that seeks to put a watershed in motion. Learn more and find other multimedia stories here.



blog comments powered by Disqus