Squaretail: The Definitive Guide to Brook Trout and Where to Find Them, by Bob Mallard

Brook trout are native in the Eastern United States and were the most important fly rod gamefish for early anglers, until they were supplanted by nonnative brown and rainbow trout. Today, brook trout are indicators of cold, clean water and healthy ecosystems, and in almost every place they are found, anglers will also find wild country and relative solitude. They have been introduced throughout the Rocky Mountains, where they grow large and abundant.
This is the most complete guide to brook trout ever written and not only includes information on tackle and techniques but important conservation information and an in-depth section on top brook trout destinations, from Maine to Argentina. With a foreword by Ted Williams.