Highland Council has confirmed plans for improvements to the northern approach to Laxford Bridge on the A838.
It intends to upgrade a 1,038-yard (950-metre) long section from single track road with passing places, to a single carriageway 6.5-yard (6-metre) wide.
Councillors will consider making alterations to the existing road and incursions into the adjacent ground, part of which is within the Loch Laxford Special Area of Conservation.
On the advice of Scottish Natural Heritage, a survey has been undertaken for mammal species protected under European law, in particular otters.
It noted that all signs of nearby otter activity were outwith the working corridor for the proposed upgrade, but that "adequate mitigation" must be adopted during construction to minimise disturbance and safeguard the species.
The survey also concluded that it is likely pine martens, another protected species, pass through the surveyed area while feeding, but no dens were found during the survey.
The bridge, which was built by the Duke of Sutherland in the 1830s, was partly demolished by an Army transporter during a training exercise three years ago, blocking access to and from north west Sutherland and leaving a detour of up to 100 miles for the heaviest of traffic.
The eight-wheeled Army lorry, which was transporting another vehicle, careered into the bridge’s parapet and toppled 30 feet into water below. No-one was injured.