COPS say they fear missing mum Nicola Bulley may have left the river on a path not covered by CCTV.
For days police have been working on the "hypothesis" that the mum-of-two slipped into the icy water and drowned.
But cops have said there was still a "possibility" she left the area on one path not covered by cameras.
The path is crossed by the main road through the village.
Officers are now trying to trace dashcam footage from 700 drivers who passed along the road at the time Nicola disappeared, around 9.20am on January 27.
It comes after a dive expert scouring the river in the search for Nicola said his team will end their efforts.
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Peter Faulding said they have done all they can to try and find the missing mum.
He told reporters yesterday: “Wherever she is I hope closure comes soon.
"All the family are clearly distraught."
Discussing search progress, the dive leader said there is simply "no sign" of Nicola near to where she vanished around St Michael's on Wyre, Lancashire.
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He explained: "We've cleared completely the area where the bench is and about a mile up from the bench, where the phone was initially found.
"We've run the side scan sonar from here down to the next bridge, which is about three or four miles away and there is no sign of Nicola in that particular area.
"We've done very thorough searches all the way down to the weir. I'm totally baffled by this one, to be honest.”
It comes as distraught partner Paul Ansell visited the scene yesterday morning.
He spent 10 minutes walking the river bank near the bench where the mum's phone was found, still connected to a work Teams call.
Nicola, a mortgage adviser from nearby Inskip, was last seen walking her dog at around 9.15am the day she vanished.
I'm totally baffled by this one, to be honest
Peter Faulding
She had dropped off her daughters, aged six and nine, at school before heading to the towpath near the River Wyre.
Monday's search for Nicola focused downstream on the tidal area of the river but Tuesday's search took place further upstream.
It included and went beyond the area where Nicola's belongings were found on a bench near Garstang Road.
It is a non-tidal area of the river.
Other dive teams started to look further upriver towards Fleetwood and the Irish Sea on Tuesday.
Cops are focusing search efforts on the track from the fields, where she was last seen, to Garstang Road in St Michaels on Wyre, which may hold vital clues.
Police had said they were confident, after reviewing CCTV, that Nicola, from nearby Inskip, did not leave the field near the river via Rowanwater.
This is the case for leaving either through the site itself or the piece of land at the side.
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And she did not return from the fields along Allotment Lane or via the path at the rear of the Grapes pub onto Garstang Road.
It comes as a heartbreaking photo of Nicola celebrating her 45th birthday emerged.