Heat oven to 375°F Grease bottom only of 9x5-inch loaf pan with shortening or cooking spray.
In large bowl, stir Bisquick mix, sugar, oats, bananas, milk and eggs until moistened; beat vigorously 30 seconds. Gently stir in blueberries. Pour into pan.
Bake 45 to 60 minutes or until toothpick inserted in center comes out clean. Cool 10 minutes. Loosen loaf from sides of pan; remove from pan and place top side up on cooling rack. Cool completely, about 2 hours, before slicing.
High Altitude (3500-6500 ft): Add 1/4 cup Gold Medal® all-purpose flour with ingredients in step 2. Bake 55 to 60 minutes.