I cannot say where the entire film was shot, however, on the DVD jacket from the Universal Screen Ledgends Collection for James Stewart (printed 2007) it states "300 local Oregon citizens were hired as extras, earning $15.00 per day to play Union and Confederate solders in the climatic battle scene." It seems at least one scene was filmed in Oregon.
No it was filmed in California. I saw it as a kid. I was living in the Shenandoah Valley then. I never could figure out where in the Valley they filmed it. When I moved to CA - I figured it out!
There was no movie filmed
This movie was filmed in DURANGO, MEXICO
The movie Before and After was filmed in various locations in Massachusetts.
Most of it was filmed in Canada.
My Girl was filmed in Bartow, Florida.
There was no movie filmed
The movie was filmed in East Corinth,VT. We have a cabin there.
The movie Sliding Home was filmed there.
This movie was filmed in DURANGO, MEXICO
The movie Before and After was filmed in various locations in Massachusetts.
the movie that was filmed on Pandora's Navis was Avatar
The 1963 movie Cleopatra was filmed at the Cinecitta Studios in Rome.
It was filmed in Brazil and LA
It was filmed in 1996.
It was filmed in Chicago.
The movie Eragon was filmed in Hungary.
Most of it was filmed in Canada.