Service New Brunswick provides aerial photos online. If you look at the ones of the bog country of Kent County, you can see "trail lines". These are lines that still exist. They were made by caribou over thousands of years.
I have never seen a caribou. My gramma Owens told me of them. Back in the 1890s, the caribou would migrate past their farm, nose to tail during daylight, for over four days.
I have walked such trails... two to four feet deep. I have a set of antlers. Gramp Owens' father shot one in spring when the rivers and fields stayed frozen late. He didn't want to take a moose because he knew the meat would be near as bad as caribou after the hard winter.