Riederalp is a municipality in the district of Raron in the canton of Valais in Switzerland. It was created in 2003 through the merger of Goppisber…Riederalp is a municipality in the district of Raron in the canton of Valais in Switzerland. It was created in 2003 through the merger of Goppisberg, Greich and Ried-Mörel. Riederalp has an area, as of 2011, of 21 square kilometers. Of this area, 27.7% is used for agricultural purposes, while 42.0% is forested. Of the rest of the land, 3.0% is settled and 27.3% is unproductive land.