It was on January 19, 1919, that George Graf, Otto A. Hiller, Ed Meier, Carl N. Petersen, Dye Petersen, and Otto F. Zottman, under the guidance of the Rev. Martin L. Mueller, then pastor of St. Peter's Lutheran Church in Monte Vista, Colorado, associated themselves as charter members of Trinity Evangelical Lutheran Church of Alamosa. The organization meeting was held in the Seventh Day Adventist Church on the North-West corners of Main Street and Edison Avenue in Alamosa. Pastor Mueller had been conducting services in Alamosa for many years prior.

Even before formal organization of Trinity Lutheran Church Pastor Mueller held Lutheran services in the Adventist Church. A copy of the minutes from a church business meeting that took place on February 8, 1920 reveal that rent was being paid to the Adventist church in a total sum of $24.00. Some of Trinity's earliest church services were even held in City Hall in Alamosa.

In 1922 the church decided to purchase the Roman Catholic Chapel located on the block where the Post Office is today. They purchased the chapel for "no more than $1,000.00" and moved the structure to the corner of Fourth Street and Alamosa Avenue.

 The original building remained 39 years until they built the current worship center at 52 El Rio Drive, its current location. The construction of the worship center  was completed January 15, 1961. When the big day arrived the congregation assembled to dedicate its beautiful new house of worship to the glory of God, who had showered His blessings upon their gathering and had sustained them  for 42 years thus far. They also held a banquet that day for the dedication. It was attended by over 600 people!!

Charter members of Trinity also founded the Alamosa Hospital which is now the San Luis Valley Regional Medical Center. Members of the congregation still serve on the board at the Hospital to this day. 

2023 has been filled with much construction and updates to the building!! Structural problems have been repaired and much remodeling has been completed. The worship space and fellowship hall have new carpet and the most recent upgrades are the new pew cushions. Simultaneously, Trinity continues to support it's Christian Day School "Trinity Lutheran School" which offers high quality Christian education to preschool-2nd grade students. This year the church,  in cooperation with Easter Seals, began a new ministry to the citizens of the San Luis Valley. Together they offer respite care on Saturdays for families of developmentally disabled people. Trinity also continues to offer both adult Bible Study and Sunday School every Sunday morning, as well as Divine Service each week. The church also offers Theology on Tap where Pastor Jason gathers with interested people at a local craft brewery to discuss practical theological topics and offers guidance from God's Word on how to understand and deal with some of the more tricky cultural issues people face today.  God has many blessings in store for Trinity, just this last quarter the church has added 11 new members!