A group forming a trust to purchase land in White Salmon, Klickitat County, and Hood River County for construction of affordable housing has taken another step forward.  The Big River Land Trust on Monday was notified its incorporation as a non-profit in the state of Washington has been certified, and expects the same in Oregon in the next month.  White Salmon Mayor David Poucher says they aren’t ready yet to take donations, but they are getting closer.  Their goal is to get 40 to 100 units into home ownership “fairly quickly.”  The land trust would retain the property the homes are built on, limiting appreciation on the homes to one-and-a-half percent per year.  Poucher said the target group will be those making between 60 and 120 percent of the median income in the region.