“Poor New Mexico! So far from heaven and so close to Texas”

“Poor New Mexico! So far from heaven and so close to Texas” was allegedly said by New Mexico governor Manuel Armijo, about 1850. The phrase has been placed on bumper stickers. I couldn’t find early, verifiable historical citations for this phrase, made popular by a novel in the early 1970s.
   
   
http://en.wikipedia.org/wiki/Manuel_Armijo
Manuel Armijo (c. 1793–1853) was a New Mexican soldier and statesman who served three times as governor of New Mexico. 
 
 
25 November 1973, Los Angeles Times, pg. S70:
So Far From Heaven by Richard Bradford (Lippincott: $6.95).
(...)
Titled from Territorial Gov. Manuel Armijo’s classic remark in the early 1800s, “Poor New Mexico! So far from Heaven and so close to Texas,” this is Bradford’s second novel.