L.L.Bean offers its L.L.Bean Men's Trail Pants in Walnut or Kelp Green for $34.99. Coupon code "TRAIL" cuts them to $27.99. With free shipping, that's $17 off and the lowest total price we could find. It's available in regular sizes S to XL, although not in all size/color combinations. Deal ends March 19.
Note, they're also available in tall sizes for $35.99 via the above coupon.