Russell, whose character lives for a time with the Indian tribe, says she worked with Cheyenne advisers to learn some of the language, "because you also have to understand even if you're not speaking, you have to understand the scenes."
After all that study, however, she says she can't remember any of it.
"Oh, for the love of God, no. Literally, Hebrew's easier, much easier than this. It was so hard, so hard."
Russell, 29, became a TV star as the title character in the series "Felicity (search)," which aired on WB from 1998-2002.
"Into the West," which also stars Tom Berenger, Beau Bridges, Josh Brolin, Keith Carradine, Jessica Capshaw, Matthew Modine, and Skeet Ulrich, spans 65 years of history in the Old West.
Friday night's first chapter, "Wheels to the Stars," airs at 8 p.m. EDT, with encores Saturday and Sunday. New episodes will be shown every weekend for six weeks.