1. Preheat oven to 350°F. In a medium bowl, beat butter, brown sugar, and maple syrup with an electric mixer on medium speed until light and fluffy.
2. Add flour, oatmeal, and salt to sugar mixture and mix until blended. Stir in walnuts. Drop by teaspoonfuls 2 inches apart onto greased cookie sheets.
3. Bake 12 to 15 minutes, until set. Let cookies cool on sheets 2 minutes, then remove to a rack and let cool completely.