Here's a little-known outing...Far Horizons, as described by Netflix:
At the request of President Thomas Jefferson, in 1803, explorers Meriwether Lewis (Fred MacMurray) and William Clark (Charlton Heston) set out to explore the untamed, trackless Western lands recently purchased from France (in the Louisiana Purchase).
That sounds like good casting... I'm interested... then we have this info:
Donna Reed portrays Indian maiden Sacajawea, who helps the explorers.
Now, that is Hollywood being Hollywood as only Hollywood can.