M.T.
There is an alternative school in Hadley called North Star and they work with families who are educating their kids using alternative methods and organization. They would likely be able to refer you to educational organizations that provides certificates (high school diploma?) of completion.
More and more colleges are interested in kids that have completed high school through alternate ways and are no longer requiring high school diplomas. I know this is true for the top tiered colleges, and maybe likely for the state schools, as well. Good luck.