The window for public enjoyment of a car-free Stillwater Lift Bridge will close this spring, but the inconvenience will be temporary.

By next April, the area surrounding the historic bridge in downtown Stillwater will be fenced off as a staging area for the construction company hired to convert it into a pedestrian and bicycle link for a river loop trail.

The closed area will include the bridge's circular concourse on the eastern end, where several community events were held after the last vehicles crossed it on Aug. 2.

The conversion is one of the final stages of a $646 million two-state project that built the new St. Croix River bridge downriver at Oak Park Heights.

The financing package included cultural and historical improvements, including preservation of the Lift Bridge.

The old bridge will be fitted with new components to keep its lift operating for years to come. One of its spans will be removed next summer to allow boats to pass underneath while repair work is done on the lift.

Restoration of the bridge to its original appearance will include repainting it with a coat of "federal green," the color of the bridge when it opened in 1931.

Lampposts of the kind that stood along the bridge all those years ago will be installed, and workers will replace the pavement with a trail surface for people who walk and roll.

The Minnesota Department of Transportation has hired Kraemer North America, a Burnsville company, to do the conversion work.

Stillwater's Downtown Parking Commission has recommended using a portion of the street leading to the bridge and an adjoining parking lot for the staging work.

Fencing would be installed next April and removed in June 2019, said Bill Turnblad, the city's community development director, in a memo to the City Council. The council hasn't yet approved the staging plan.

Once the bridge conversion is completed and the remaining portion of the new loop trail is constructed, walkers and cyclists will be able to follow a route through St. Joseph Township on the Wisconsin side of the river. The trail follows along the river on the Minnesota side and will cross both bridges.

Stillwater officials favor a plan to convert two blocks of Chestnut Street, and the concourse at the foot of the Lift Bridge, into a pedestrian plaza. The plaza would become a community gathering place and a trailhead of sorts for people using the new trail.

A separate connecting trail also would link the bridge trail with the new Brown's Creek State Trail at the north end of downtown.