The artist Christo took a close look at the Arkansas River, which he hopes to one day cover with fabric panels, by going on a rating trip. The Pueblo Chieftain reports this is the first time the New York-based artist has tried rafting. “Before we were always working to pinpoint fabric panel locations and it was almost foolish to think of taking rafting pleasure, but we said someday we will do it and someday has come,” Christo told the newspaper. Christo's plans to suspend 5.9 miles of silver…