Bridge inspections report shows improvements; wheel tax funding helped secure $7 million in grants

Pennington County highway staff and KLJ Engineering presented the county’s 2025 bridge‑inspection summary to commissioners on Dec. 2.

KLJ’s Sean Mayfield said inspectors reviewed 68 structures this year: 62 showed no change in condition, four had improvements (preservation or replacement work), and two were documented with deficiencies—one for embankment erosion and another for timber‑decking wear. Mayfield reported no critical findings requiring immediate closure.

County Highway Superintendent Joe Miller walked the board through recent full replacements on Highway 1416 (a triple-cell box culvert replacing a 1924 timber structure) and Thunderhead Falls Road, and preservation work on Old Hill City Road. Miller and staff explained that some timber structures (e.g., a 1950 timber bridge near New Underwood) remain on a 12‑month inspection cycle because of accelerated deterioration and are programmed for replacement.

Miller credited the county wheel tax for allowing the county to apply for larger state and federal bridge improvement grants. Since 2019, the county has spent about $13 million on bridge replacements and preservations; Miller said the county’s local share totaled about $5.2 million while roughly $7 million was secured from federal and state programs via grant awards.

The board asked staff to continue monitoring at‑risk bridges, to program replacements with grant opportunities in mind and to coordinate with affected landowners when easements are required for replacements.

Next steps: continue inspections, program replacements and preservation projects, and pursue grant opportunities; staff will return with detailed project schedules and funding plans as bids and grant awards are finalized.