The world's largest salmon cannery was operated by the Alaska Packers' Association for decades in Blaine; the cannery site has been converted to a waterfront destination resort on Semiahmoo Spit. Several saw mills once operated on Blaine's waterfront, and much of the lumber was transported from its wharves and docks to help rebuild San Francisco following the 1906 fire there. The forests were soon logged but Blaine's fishing industry remained strong into the second half of the 20th century. Into the 1970s Blaine was home to hundreds of commercial purse seiners and gillnetters plying the waters offshore of British Columbia, between Washington state and southeast Alaska. Blaine's two large marinas are still home to hundreds of recreational sailboats and yachts. Nature lovers have always appreciated Blaine's coastal location, its accessible bike and walking trails, and view of mountains and water. Birdwatchers across the continent have discovered the area's high content of migratory birds and waterfowl: Blaine's Drayton Harbor, Semiahmoo Spit and Boundary Bay are ranked as Important Birding Areas by the Audubon Society.