Miles off the coast of northern California lies a mariner's nightmare. Concealed by roiling sea and thick fog, the jagged edges of a submerged volcanic mountain chain await approaching vessels like predators in the mist. This is one of the most hazardous reefs off the West Coast. And for over a century, it has been home to the most remote, most expensive, and most dangerous lighthouse ever built in America. Called "Dragon Rocks" in 1792 by British explorer George Vancouver, the area became known as St. George Reef in the hope that its namesake might slay the dragon. But the beast claimed its greatest victim in 1865 when the side-wheel steamer S.S. Brother Jonathan sank on one of the rocks with the loss of 225 souls, inspiring an extraordinary effort to make the waters safe. The result took ten years to construct and cost as much as twenty conventional lighthouses. In Sentinel of the Seas, Dennis M. Powers chronicles the heroic stories of men and women who have gone where land and sea collide. To build the St. George Reef Lighthouse, Alexander Ballantyne—probably the only man alive who was qualified and brave enough to supervise such a project—faced incredible hurdles, including the haul of six-ton granite blocks onto a spit of washed-over land from a quarry seventy-five miles away. In 1937 George Roux, the tough, longtime head lighthouse keeper, was trapped for two months by howling winds and stories-high waves with his crew on the verge of mutiny. In 1951 a rogue wave capsized a Coast Guard launch being lowered from the lighthouse, challenging keeper Fred Permenter to attempt a nearly impossible rescue that would win him a place in Coast Guard history. Based on five years of research drawing on the National Archives, original journals, and personal interviews, Sentinel of the Seas is the first book to capture the tumultuous history of this astounding engineering feat and the lives that have been influenced by it. The author takes readers back to the dawn of lighthouse design, charting the dramatic moments and the courageous people who have shaped a struggle against the oceans that culminates in the singular experience of St. George Reef. A vivid, comprehensive work of history that reads like the best adventure writing, this portrait of human tenacity and the raw fury of nature solidifies Dennis M. Powers' reputation as one of our finest chroniclers of the sea.