Despite months of continuous torrential rain, blazing sunshine and clear blue skies are visible in several shots of Walnut Grove.
Zachariah claimed to have dug the two mines twenty years earlier (in the early 1860s, therefore). However, the Dakota Gold Rush did not begin until 1874, and no shaft mining - as opposed to placer mining - took place before the Homestake Mine in 1876. The Black Hills generally were closed to non-Indians before 1874.
It has been established in earlier episodes that Isaiah Edwards is illiterate. However, the plot for this episode centers on Isaiah showing Charles a newspaper article he had read about gold in the Dakota Territory. *However, in the season two episode, "His Father's Son", Isaiah is shown at the end teaching himself to read.
The morning after the rain finally stopped, the grass and prairie is bone-dry and appears not to even have any ill effects of the two-month long rain.
At 19:36 when the wagon is shown at sunset, airplane contrails can be seen in the sky.
Although it's raining heavily in Walnut Grove at the beginning of the story, you can tell quite clearly that the sun is out.
Caroline covers her head with a shawl to protect her from the rain when she goes to the barn to talk with Charles. When she goes inside the barn the shawl is completely dry after being drenched by rain.
There is no physical evidence that Mr. Griffin dug up Lorraine's grave.
As Charles is walking away from the mercantile after paying his bill, a carriage is seen crossing the bridge. You can see the rain falling in different directions at once.
When Isaiah and Grace are driving through the town, their wagon is briefly reflected in a shop window revealing it is a disguised modern trailer with all-terrain, rubber tyres.
Jack the dog was on the trip but seen nowhere in the town of Newton.