By Cheri Sayer The Highline Historical Society has a well-established presence in South King County, and soon it will have a new home and it’s very own Museum!  Founded as the Burien Heritage Society in 1994, it soon merged with the Friends of the Highline School District and became the Highline Historical Society.  They have been an active society, with a small exhibit space at the SeaTac City Hall for quite a few years.  The Highline community has been the largest area in the State of Washington without a local history museum, so this effort has been a long-time goal of the Society.             The community of Highline is not a governmental entity, but a school district, known locally as “401” or the Highline School District.  The Society defines Highline as being bounded on the north by Seattle city limits, on the west by Puget Sound, and on the south at 252nd Street, just at Salt Water State Park.  Hwy 5 forms most of the eastern boundary.  It covers White Center, Burien, No