Christo and Jeanne Claude are pressing forward with their plans to cover part of a Colorado river with fabric. “State, local and federal governments permitting, “Over the River” would occur over two midsummer weeks in 2008, at the earliest, the husband-and-wife team said. Their display, whose seven increments would range from a half mile to 2 1/2 miles long, is designed to be observed from above by motorists on U.S. 50 and from below by hikers and rafters, they said. The fabric is designed to reflect the sky for those watching from above and to diffuse the light when seen from below.”