In small bowl, whisk together lemon juice, 1/4 cup maple syrup and mustard. Add 1/3 cup plus 1 tbsp olive oil, whisk until smooth. Whisk in 1/4 tsp salt and 1/8 tsp pepper.
Place oven rack in middle of oven. Tightly wrap beets in foil. Heat oven to 400. Roast beets for about an hour or until tender. Cool. Peel. Place squash on jelly roll pan. Toss w/ remaining 1 tbsp oil, 1/4 tsp salt and 1/4 tsp pepper. Roast for 15 mins. Drizzle w/ remaining maple syrup. Roast until tender, about 10 mins. Cool.
In lg serving bowl, toss salad greens w/ beets, squash and walnuts. Add raisins to vinaigrette dressing. Pour half over salad. Toss, serve w/ remaining dressing.