Plans to replace the aging Champ Clark Bridge at Louisiana are approaching a big roadblock.

An environmental study for a new crossing should be done by the end of the year. But unless new dollars are found, Missouri won’t be able to proceed with design work as 2016 begins.

Crews have completed replacing 15 hundred original rivets on the 87-year-old structure. The project was finished five weeks ahead of schedule and no more major work is planned until next year’s annual inspection in August.

Missouri and Illinois will split the cost of building a new bridge just south of the existing one. The states are seeking a federal grant to offset the 60 million dollar cost.