BURLEY — Take either of the Interstate 84 exits to Burley, and you’re likely to cross the Snake River.
But unlike in Twin Falls, where the river flows hundreds of feet below a canyon rim, the river flows right through town in Mini-Cassia.
The Overland and Heyburn bridges move traffic between Minidoka and Cassia counties and facilitate the flow of commerce for Burley and Heyburn. The bridges provide vital access to I-84, which has been the main driver for Burley’s growth, Economic Development Director Doug Manning said.
The historic crossings predate the interstate, but larger replacement bridges were constructed to accommodate the traffic increase generated by I-84.
For now, the bridges are still sufficiently moving drivers along.
“There’s not a lot of congestion, and it’s short-term congestion,” Idaho Transportation Department spokesman Nathan Jerke said.
Along U.S. 30, two prestressed concrete girder bridges span just over 1,312 feet across the river between Burley to the south and Heyburn to the north.
The Heyburn Bridges, which are two lanes apiece, replaced an older bridge that had a single lane in each direction and no sidewalk. After U.S. 30 expanded to four lanes in the 1960s and 70s, the narrow bridge choked up traffic, Jerke said.
After that, Interstate 84 quickly overtook U.S. 30 as a primary mover for traffic. The business route off Exit 211 takes traffic through Heyburn before crossing the river into Burley.
“The bridge was really one of the last steps to complete that business loop,” Jerke said.
ITD constructed the southbound bridge first, in 1977, alongside the original bridge. The northbound bridge was constructed the following year. Jerke said the project was likely done as two bridges so that traffic could be maintained.
In 2011, ITD removed an asphalt overlay, applied a crack sealer on the decks, and repaired and waterproofed the parapets and sidewalks.
Finally, crews replaced expansion joint seals and added snow plow deflector bars across the top of the joints.
The Heyburn Bridges, last inspected in August 2016, were in “satisfactory” condition — a good score, Jerke said, considering their age. Replacement bridges will not be considered for at least 30 years.
The Overland Bridge along Overland Avenue/Idaho 27 connects the original Burley townsite in Cassia County to the “interstate-era townsite” of north Burley in Minidoka County.
“The bridge really ties together two commercial areas of Burley,” Jerke said.
ITD replaced the older, 1947 bridge in 2001 with a prestressed concrete girder bridge that’s 849 feet, 9 inches long. It took 2 1/2 years to finish.
The state built the new bridge at a higher elevation so boats could pass underneath more easily. The former bridge also had more vertical structures in the water.
The four-lane Overland Bridge is a busier commercial corridor than the Heyburn bridges, but is still rarely backed up between traffic signals.
“It’s really only on the busiest of days and the busiest times of day when we see traffic slow down,” Jerke said.
Children sometimes jump off the Overland Bridge on the Minidoka County side and swim to a nearby park. Warning of potential hazards in the shallow water, Minidoka County attempted to outlaw bridge jumping in 2012. As of October, it was still legal, according to the Minidoka County clerk.
In 2010, ITD did driving surface improvements with an epoxy overlay on the deck. The project also replaced expansion joints, did some waterproofing and repaired concrete.
At only 16 years old, ITD does not expect the bridge to require any major renovations soon.
“As long as we continue the regular maintenance on the bridge, it should be there a good long time,” Jerke said.