The best news observers of the dwindling trumpeters could ask for came in the early 1950s when a Pacific Coast population of several thousand was discovered during aerial surveys near Alaska's Copper River. These birds summer in Alaska and migrate south in winter to coastal areas of Canada and Washington. This vigorous population has grown steadily since its discovery and is now estimated at 16,000 swans. A few have made their way into Oregon and are now coming into California. The infrequent trumpeter seen in California in the 1930s and 1950s probably came from this population.
Most trumpeters now entering California appear to come from the Rocky Mountain population.
This once-tiny population, clustered around Yellowstone, has grown over the past 60 years, increasing to about 3,100 birds. Reducing illegal shooting, protecting habitat, controlling water flows in dammed areas, and supplemental winter feeding brought this population away from the brink. Most of these swans migrate to Canada for the summer, but about a quarter of them stay near Yellowstone year-round. They lived in an artificial Eden specially stocked with grain to see the swans through each winter. Furthermore, the unnaturally large population of swans degraded the habitat for fish and other waterfowl.