Here is a link to their story. It is lengthy but well worth printing out and reading. http://catholicism.org/eight-na-martyrs.html
And here is a link to the Auriesville Shrine. http://www.martyrshrine.org/pages/saints-of-auriesville.html St. Kateri Tekawitha was born near Auriesville several years after the missionaries were martyred. The shrine is well worth a visit. In our country it is not often we get the opportunity to visit the actual site where some of our brothers were martyred for their faith.