Now how much license the Disney Studios took with the expedition is open to interpretation. I suspect there was some license taken to make it an interesting story for the juvenile audience it was primarily marketed for.
John Beal plays the one armed former major in the union army who was with its topographical corps and who spent the Civil War surveying and map making for the top Union brass. It's where he lost his right arm. James Drury plays his younger brother Walter who has his own set of issues regarding the late war where he was in Andersonville prison. He and former Confederate Ben Johnson have their conflict which is one of the subplots.
Brian Keith plays one of his patented frontier characters who leads a mutiny among the men who are not sure when or if they'll come to the end of the Colorado gorge. Keith is always interesting in any film and right about now he was in about every other Disney film out there, or at least every one that Fred MacMurray wasn't or so it seemed back when I was a lad.
Nice location cinematography is the most distinguishing feature of Ten Who Dared. I think more than a juvenile audience will appreciate this film.