The Ben Tyler trail is on the highway and well marked about two miles west of Shawnee. This trail leads to a large grove of aspen several miles in. The Colorado Trail runs along the ridge crossed by Kenosha Pass. Either way from the highway provides aspen and great views of South Park without much change in elevation. The best time for viewing the aspen is hard to predict.
Weather is a major force in how long the aspen hold their leaves after they turn.
With good weather they can last for weeks, but one storm can strip all the trees bare. In general, September's weather in Colorado's backcountry is favorable. The daily afternoon thunderstorms of the summer months stop near the end of August and there are many cloudless days great for climbing peaks. However, the occasional snow storms also start coming through in August. The backcountry visitor should be prepared for snow as many have found themselves waking to beautiful snow scenery.