Carson Ellis is the illustrator of many books for kids, such as The Mysterious Benedict Society and Lemony Snicket's The Composer is Dead. I first noticed her work in Wildwood, written by her husband Colin Meloy, who I knew of because of his indie band The Decemberists, which I knew about because I had once picked up their CD in a record store . . . because of its amazing cover illustration.
She uses a muted palate of colors and her illustrations have the old-timey feeling of folk art. They are simple and two dimensional, like Grandma Moses, except where Grandma Moses painted realistic scenes of everyday life, Ellis draws imagined life. Wildwood tells the story of Prue, whose little brother gets kidnapped by a lot of birds and she must enter the Impassable Wilderness to get him back. The premise is that Portland, Oregon's Forest Park — an 8-mile park within the city limits forested with old growth trees — is host to a hidden world of strange people, talking animals and bandits; and only those who can see the Ghost Bridge (St. John's Bridge), can find their way in. There are three books in the series.