You might start with colleges with established study abroad programs in Spain, such as those of Middlebury or Hamilton, here listed in a Swarthmore website:
https://swarthmore.studioabroad.com/index.cfm?FuseAction=Programs.ViewProgram&Program_ID=34309
https://swarthmore.studioabroad.com/index.cfm?FuseAction=Programs.ViewProgram&Program_ID=10515
Beyond Middlebury and Hamilton, Swarthmore itself would be a solid choice, as would schools such as Williams, Amherst and the Claremonts.