Volunteers with Kent Harrison Search and Rescue have narrowed their search for a missing Vancouver couple to a waterfall that feeds into Statlu Lake, after finding two items on Thursday.

For the third straight day, crews are searching for 34-year-old Sophie Dowsley and her 44-year old partner, Gregory James Tiffin.

The couple was last seen on Saturday at a business in Harrison Hot Springs. It's believed they were setting out for a hike in the area. When they didn't show up for work on Monday, a family member contacted police.

On Wednesday, their pickup truck was found near Statlu Lake, about 75 kilometres northwest of Harrison Hot Springs.

Search continues in steep terrain

Statlu Lake Trail Waterfall

Search and rescue personnel believe they have found two clues that suggest the couple visited this waterfall, which is said to be treacherous with a partially-hidden, steep edge. (ihikebc.com)

The trails around Statlu lake can be difficult to access, according to rescue crews.

"It's not an easy place to get into," said Neil Brewer, with Kent Harrison SAR.

"And I can't emphasize this enough: it has some extremely dangerous spots, with a very dramatic and very dangerous waterfall that exits from Statlu Lake."

On Thursday, Brewer said crews found two signs the couple had been at that waterfall. One item was in the water below, the other on a rock slab near the top of the falls that's known to be treacherous.

"It's very slippery. People are tempted at that point — because they can't actually see the falls — to keep inching out on this rock slab to get a picture of the falls," said Brewer.

"And then, they slip and enter into the falls. At that point, they're swept down into a pool about 200 feet [60 metres] below the falls."

Brewer said he knows of three fatalities that have happened on this same area of rock.

Crews are conducting both ground and water searches.

Brewer says based on what they've found so far, it's clear the couple had only planned to set out for a day hike.

According to the RCMP, the couple lived in Vancouver, but Dowsley is originally Australian. A spokesperson said on Wednesday, members of her family were flying to the Lower Mainland in hopes of helping with the search.