According to Story County Conservation Director Steve Lekwa, work is presently taking place on the most challenging part of the Heart of Iowa Nature Trail so far, approximately 3.8 miles from Cambridge to County Road S-14. The toughest part of that challenge is bridging the Union Pacific Railroad tracks and the Skunk River.

Designated for hiking, biking, nature viewing, equestrian use, cross-country skiing and snowmobiling, the trail eventually will stretch 32 miles, from Slater to Melbourne. To date, a little more than half of the trail has been completed, from Slater east through Huxley to Cambridge, from Maxwell to near Collins and from east of Collins to east of Rhodes.

This summer, grading work began on portions of the trail from Cambridge east as well as preliminary work on the two bridges.

"We had hoped to finish work on the bridges by winter, but the long-delayed start due to flooding and prolonged time to reach an agreement with the (Union Pacific Railroad) make that highly unlikely," Lekwa said.

The old river bridge, the Chicago Milwaukee & St. Paul double-track railroad bridge, was built in 1912 and dismantled in 1982. Its original concrete piers were left and will serve as the supports for the new bridge.

"A great deal of surface repairing needs to be done to the piers," Lekwa said. "We finally were able to get concrete testing done on the structure during the past week now that the crane can lift the heavy coring drill up to the tops and sides of the piers.

"The latest test results by the engineering consultants made Thursday indicate that we will also have more repairs to do before any construction can begin on top of the piers."

One of the major projects necessary for the testing and bridge work was to build a temporary causeway across the river so that a large crane could travel from span to span. The concrete rubble causeway has four large steel culverts that allow the river to pass through it.

"A winter like last year would stop us dead in our tracks until spring and maybe later since we might then have to rebuild the temporary causeway across the river," Lekwa said.

Because of the anticipated added expense of the pier work, Lekwa said it looks like just the bridges and approach slopes will be concrete paved and the rest of the trail to S-14 will be compacted limestone.

"We're not sure where all the extra money is going to come from and will hopefully be getting a clearer picture of the extent of extra work needed this week as our engineers digest the data," Lekwa said.