The Knights Ferry Bridge — the longest covered wooden bridge west of the Mississippi River — will be undergoing extensive repairs.

The Army Corps of Engineers closed the bridge as of Friday, Dec. 30.

The closure follows a structural analysis that determined significant wood deterioration has compromised the stability of the 330-foot historic covered bridge.

The bridge will be closed to pedestrian traffic for an undetermined amount of time until either temporary supports are installed or full rehabilitation of the bridge is completed.

The Army Corps since July has limited the number of people on the pedestrian-only bridge at any given time and confined its use to the middle six feet.

Consultations with the California State Historic Preservation Officer will ensure that all modifications safeguard the 159-year-old bridge’s status on the National Register of Historic Places.

Built in 1863, the covered bridge spanning the Stanislas River east of Oakdale a mile north of Highway 108/120 via Sonora Road is considered one of the best-preserved 19th century wood-iron Howe truss bridges still around. The bridge sections consist of Howe trusses crafted from wooden planks bolted together via wrought iron tension roads. The bridge’s exterior is finished in vertical wood siding with a metal roof.

Near its northern end are the ruins of a mill and what was California’s first hydroelectric plant.

The bridge is the focal point of the Knights Ferry Recreation Area, one of 16 recreation areas the Army Corps operates on the Stanislaus River between Knights Ferry and the river’s confluence with the San Joaquin River.

It is the starting point for low-key rafting trips.

Knights Ferry was founded by Captain William Knight, who was part of John Charles Fremont’s Expedition of 1844. It was the second of two expeditions he was ordered to tackle by the Corps of Topographical Engineers to chart roues to the western edge of the continent.

The first was in 1842. It resulted in the surveying and mapping of what was to become known as the Oregon Trail. The 1844 expedition was conducted to find a more southern crossing of the Rockies and explore the areas south of the Columbia River. He ended up crossing into what was then the Mexican province of California.

Initially Knight operated a ferry across the river that was used by those heading to and from the gold mines. There was also a hotel at the crossing.

Knights Ferry became a center of mining activity as well as a distribution point for supplies moving to the Mother Lode. Knights Ferry served as the county seat of Stanislaus County from 1862 through 1872.

Today, Knights Ferry is the most accessible as well as the largest of the river parks. The rafting companies aren’t running again until spring but you should keep them in mind if you want to enjoy a mellow time on the Stanislaus River when spring weather returns.

Knights Ferry’s appeal is in its diversity for visitors. You can get right to the river’s edge. You can explore river woodlands. You can hike a trail along the riverside northeast of the bridge that takes you to the Takin Rancheria where you’ll find bedrock mortars. Beyond that the trail takes you to sandy beaches, some swimming holes and some fishing holes that are favorites with regulars.

The main area of the Knights Ferry Park is easily accessible with a number of paved trails though there is nothing stopping you from wandering off of them to explore, skip a few rocks across the water or capture photos of nature.

There is plentiful parking on both sides of the river complete with picnic and barbecue areas. There are also restrooms at Knights Ferry as there are at Orange Blossom, the second most popular spot in the river.

The last significant repairs and renovation of the bridge occurred in 1989. Updates on bridge repairs will be posted at https://www.spk.usace.army.mil/Missions/Recreation/Stanislaus-River-Parks/.