How many states did the Lewis and clark expedition pass through?

Before Lewis met up with Clark, he began the expedition on August 30, 1803 in Pittsburgh PA. Lt. William Clark would offer to join Lewis on the expedition weeks later on October 13, 1803 at Camp Dubois (in present-day Indiana).

And being that the expedition began in Pittsburgh, states the expedition passed through would include: Pennsylvania, Ohio, West Virginia, Indiana, Kentucky, Illinois, then Missouri, Iowa, Nebraska, South Dakota, North Dakota, Montana, Idaho, Oregon and Washington.

If you don't believe that the Lewis and Clark expedition began in Pittsburgh, please refer to the link below and it will lead you to the first entry of the Lewis and Clark Journals.