Art and LeAnne Viall of Kinsey have announced the engagement of their daughter, Lena K. Viall, of Missoula, to Erik C. Larson of Missoula, formerly of Logan, Utah.  He is the son of Wes and Marie Larson of Logan.  The couple will exchange vows on Saturday, August 20, in Seely Lake.  They will live in Missoula.