Hello. The MIERA records I have in my database are for the family of Jose MIERA and his wife, Manuela ROMERO, who were married in 1797 [St. Francis Parish and Military Chapel of Our Lady of Light (La Castrense) 1728-1857 by NMGS page 75]. I have records for some of their children whose births span 1797-1912. Have you tried the online databases of the LDS (Mormon) library at http://www.familysearch.org
or the collection online of the Hispanic Genealogy Research Center of NM at http://www.hgrc-nm.org
I think that all the early northern New Mexico and southern Colorado Spanish families are connected, so we probably have a connection when we are able to find it. Let me know if any of this might be helpful.