The Twilight Zone - A Hundred Yards Over The Rim torrent

Christian Horn is member of an 1847 wagon train headed west. They are 1500 miles from St. Louis and are now in the New Mexico desert. Many in the wagon train are ready to turn back but Chris wants everyone to persevere. His son has had a fever for 11 days now and Chris goes off looking for water, only 100 yards or so from the others and suddenly finds himself in the present day. He can't quite bring himself to believe what he sees or where he is but those he meets believe he's a man from the past. The trip in time does have one positive outcome