Evensons in Lunder Parish

With help from people on this forum I've been able to track Norwegian relatives in Minnesota and North Dakota, now I'm hoping to find some information about their ancestors in Norway. From online records Even and Ingor Evenson emigrated from Lunder parish in June of 1876 and met their son Halvor (Even) in Spring Grove, MN. Specifically I would like to know any information about Lunder Parish and help with any further information about the Evenson's ancestry in Norway. Thank you.