86 Rock Valley, Iowa March 16, 2021 Joan Maassen, 86, of Rock Valley, Iowa, died Tuesday, March 16, 2021, at Hegg Health Center in Rock Valley. Memorial service was Saturday, March 20, at Netherlands Reformed Church, Sioux Center, with interment in Memory Gardens Cemetery, Sioux Center. Survivors include 12 children including Ronald (Joyce) Maassen of Boyden,…