Fall River is an excellent little river with fishing as good as the views.  Lots of eager brook trout await a well presented fly.  The fish can be spooky as flows get low, but there are not many big fish in this river so using 5x or 6x is recommended.  The main sections that are fishable are easy hike in access to meadowy winding rivers. The trout are in every area of the river so explore and be stealthy and you’ll have a great day enjoying the wildlife, views and trout that Rocky Mountain National Park has to offer.