Imagine an undiscovered Eden in the heart of South Dakota, a major river lying untouched and forgotten for decades – with epic fishing amidst thunderous solitude. It exists, and Dan Frasier, a pioneer of fly fishing for big carp and author of an Orvis guide to carp flies, found it: 39 miles of the Missouri River, almost inaccessible to the public, almost unknown. He was sorely tempted to keep his discovery to himself. Why he did not is a message for all American conservationists.