A TV documentary on environmentalists’ efforts to save Iowa’s near-extinct prairie will debut tonight (Friday) in Cedar Falls, with a little help from a big-screen actress who calls the Hawkeye State home. 33-year-old Annabeth Gish has appeared in 38 films and on T-V’s “The West Wing” and “The X Files.” Now, she’s narrating the documentary called “America’s Lost Landscape: The Tallgrass Prairie.” Speaking with Radio Iowa from a movie set in Florida, Gish explains why she lent her voice to the project.She says “It’s a beautiful, beautiful documentary that really brings to the forefront the discussion about an ecosystem that’s very important to Iowa. It is the tallgrass prairie and it’s an ecosystem and an environment that’s kind of disappeared over the years and this film talks a lot about the reconstruction and revitalization of our landscape.” Gish was born in New Mexico but grew up in Cedar Falls. Her dad was a professor at the University of Northern Iowa. The actress says her deep loyalty to her Iowa roots is a big reason why she worked on, and is promoting, the documentary.The film traces the prairie’s transformation from natural landscape to farmland. Iowa was once blanketed by 28-million acres of tallgrass — about 85-percent of the state. Now, it’s about one-tenth of one-percent prairie. The film premieres at 7:30 P.M. at U-N-I’s Lang Hall auditorium. Efforts are underway to get it aired soon on Iowa Public TV. For more information and to view a brief clip, visit “www.uni.edu/~lostland”.