Brother Trejo was born in Garganto-la-Olla, Spain. He recieved a liberal education and then joined the Spanish army. While stationed in the Philippines, he heard of Saints in the Rocky Mountains led by a prophet. He then had a dream which prompted him to leave the military and travel to Salt Lake City. There he met Brigham Young, joined The Church of Jesus Christ of Latter-day Saints and then assisted Daniel W. Jones in translating the Book of Mormon into Spanish.
After Brother Jones left to serve as a missionary in Arizona, New Mexico, and Mexico, Trejo completed the Book of Mormon translation. It was published in 1886. In 1884 Trejo married Emily Jones. They eventually had ten children.
After serving as a missionary with Brother Pratt, Trejo settled in the Mormon colonies in Mexico. When the Saints fled the colonies due to the rising violence, Trejo like many other settled in St. David, Arizona. He died at nearby Wilcox, Arizona.
Garr, Arnold K. et. al, Encyclopedia of Latter-day Saint history, p. 1257-1258.