CHAPTER XIV BREAKING THE ICE JAM 268 CHAPTER XV FACING DEATH IN A CANOE 290 CHAPTER XVI DECLARING WAR ON UNCLE SAM 311 CHAPTER XVII CLAWED BY AN ANGRY BEAR 328 CHAPTER XVIII FIGHTING FIRE IN THE TUNDRA 344 CHAPTER XIX RACING A POLAR WINTER 362 ILLUSTRATIONS The Chief Geographer of the United States, surveying the Sierras, with Assistant Topographer _Frontispiece_ FACING PAGE In the Home of the Kodiak Bear 8 A Lofty Spouter } Water Enough for All } 30 In the Tamarack Swamp 44 A Tangle of Swamp 54 Measuring Stream Flow 72 Difficulties of Work 76 Dense Southern Palm Grove 82 Grand Canyon of the Colorado 94 An Awkward Country to Work In 98 "How in the World am I going to get up there?" 108 A Hard Point to Measure 118 Twenty-seven Miles from Water 152 In the Death Valley 170 Crossing a Swollen Stream 176 Bridged by "Double Tree" 180 If He Should Slip! 186 A Grim and Icy Barrier 252 A General View of Tyonok 256 Farewell to Civilization 260 Where an Eternal Gale Rages 270 Morning after the Blizzard 278 Resting after a Long Pull 288 A Short but Dangerous Rapid 300 Skinning a Caribou 306 The End of a Hard Climb 310 The Only Bit of Rock for Miles 314 In Icy Water under a Burning Sun 348 Thus Far with the Boats, and no Farther! 354 Winter's Threat Almost Fulfilled 370 Eskimo Saviors } Pointing away from Winter } 376 THE BOY WITH THE U. S. SURVEY CHAPTER I A START AT THE CAPITAL "Mr. Rivers?"