If you need a pant that blends fashion and function into one perfect union, try the Halle Pant from Prana. Featuring a DWR finish to protect you during of those sudden showers, the Halle also has articulated knees so your movement has as much freedom as you. Since the temps can fluctuate in fall, you'll love the ability to roll the legs up when you're warm, or encounter some undesirable terrain.
Fabric: Nylon 97%/3% spandex: 5.3 oz/sq yd
Stretch 'Zion' performance woven with durable water repellent (DWR)