Steelhead are an amazing species. Several different strains are fall/winter spawners. Hatchery breeding may have something to do with fish that are spawning in fall/winter but it is more likely the hatchery is using a strain of steelhead that was a fall/winter spawner. Bc has several strains of fall/winter spawning fish. Steelhead have been adapting to our rivers over time and several differences exist between fish running rivers based on what they face in each individual river. A good example is the Credit having such an extreme gradient over the length of the river the fish that are natural production in the river are longer and leaner than East Ditch creeks. They were at one point all from the same strain but signifacnt advantages over time from individuals in each population have differentiated the populations in ways which suit the river they run. Not all Steelhead even return to the river they originate from. A small portion of the population of each river roam to run a different river. In this way they can spread to new rivers. Truly a diverse and amazing fish.