I found this family film to be pleasant and enjoyable even though I am not a child. It is based on the concept of a high school girl, Susan (Elisha Cuthbert) discovering that the elevator in her upper class apartment building becomes a time machine when a key on a key chain she got from a blind scientist is turned in the elevator lock. She learns how to control the machine (with some uncertainty about time of day).
The film is not a work of serious science fiction. You have to ignore the usual instability paradox associated with altering the past through time travel, i.e, the past is changed to prevent the 1881 Walker family from becoming poor, but the change means the family never got into financial trouble, so Victoria wouldn't have told Susan about the financial problems her mother had, which means that Susan shouldn't have had a reason to change the past in the first place! But other than that, there are some nice touches in the story, such as the old elevator panel, found in the apartment of the woman who secretly invented and installed the time machine, not having a space for the lock that activates the time machine feature. As in many stories for children, we need to also suppose that a child will not share startling information about a time travel device with a parent or other adult but instead hide the time traveler.
It also requires disregarding some poorly staged scenes and uninspired performances by some of the adult actors. (The child actors (Elisha Cuthbert, Gabrielle Boni, and Matthew Harbour) all were very convincing in their parts.) In one scene in the 1300s native Americans notice Susan observing and photographing them. But they don't register surprise in the sudden appearance of this blond, white skinned girl in peculiar dress. Their response is to simply stop what they are doing and to walk calmly towards Susan. In the same scene an Indian mother is carrying what is supposed to be a baby but is so obviously a doll (its white skinned and its head flops around).
Timothy Busfield, the award winning actor who originally came to fame in TV's old "Thirty Something," gives a somewhat uninteresting, sometimes listless, performance. In the other extreme Michel Perron hams it up as the Italian building superintendent (janitor), as does Richard Jutras in his role as a nosy neighbor. (The neighbor's name is Edward Ormondroyd, which is the name of the author of the novel the film is based on.) I suspect that these problems may be the fault either of the director or possible of a low budget.
Despite these flaws, I recommend the movie for kids. In addition to the interesting story, it also has some educational value, in that it points out how much both technology and social norms have changed in little more that 100 years.

Randolph Scott is leaving the USA for the greener pastures of Canada's British Columbia. He wants to start a cattle ranch there with partner Bill Williams and cook Lee Tung Foo. They stampede their small herd over a toll bridge erected by Victor Jory. Later Jory rustles their cattle and Williams loses his left arm during the fracas.
From 1945 until 1962 when he retired, Randolph Scott made a series of good adult themed westerns, some of them considered real classics. Unfortunately the Cariboo Trail will never be listed among his best westerns.
It's more like the material that Roy Rogers or Gene Autry might use. The story is downright silly at times. Williams who was along for the ride with Scott, he wanted to go prospect for gold as there was a big strike at the time. He doesn't blame the rustlers, he blames Scott for convincing him to make the trip for the loss of his arm.
Also there's a scene in the film when Scott, Lee Tung Foo, and Gabby Hayes are captured by Indians. They escape because Gabby's mule has been taught to kick on command and he kicks away at the Indians allowing our heroes to escape. I'm not sure that would have played in a Rogers film.
Furthermore the story actually wants you to believe that tyro prospector Randolph Scott accidentally stumbles on a gold strike after just a few lessons from prospector Gabby Hayes on how to find gold.
This was Gabby Hayes's farewell feature film part. It would have been better had he gone out in a good western and in fact he had done a couple of better ones with Randolph Scott before this.
I will say this, though no Caribou made any appearance in the film, this is one of the few Canadian locale films from the past that did NOT have any Mounties.
But if I were you unless you are a big fan of Randolph Scott or Gabby Hayes, take the next detour off The Cariboo Trail.