In the January-February 1999 and March-April 1999 issues of Living Church News he is listed as the publication's managing editor.
Mendiola is listed as a contact man in Pocatello, Idaho in every issue of 1999.
January 2000: "We Still Must Preach the Gospel!" (pp. 12-14.) Here he calls for LCG members to preach what LCG teaches is the Gospel.
February 2000: "Truly "Knowing the Lord."" (pp. 10-12.) Here he condemns mainstream Christians for often talking about the Lord and not observing the Sabbaths and the annual Sabbaths as is taught in LCG.
March-April 2000: "Lessons from the Red Sea." (pp. 12-15.) Here he draws upon the crossing of the Israelites through the Red Sea to call upon LCG members to adhere to (the LCG leadership's views about) God's will.
March-April 2001: Mendiola is listed as a contact man in Pocatello, Idaho.
November-December 2003: While reporting on the (improperly observed) Feast of Tabernacles it is mentioned that Mendiola preached to LCG members gathered in Florence, Oregon.
A lively 200 brethren rejoiced in fellowship and rich spiritual food in Florence, Oregon, in a majestic Pacific Ocean environment, with daytime temperatures in the 50s and 60s. Brethren heard inspiring and encouraging sermons from Mr. Bryce, Mr. Carl McNair, Mr. Don Haney, Mr. Terrence Graves and Mr. Mark Mendiola. (p. 20.)March-April 2004: "Refined Gold." (pp. 8-10, 18.) Here he encourages LCG members to expect and graciously receive fiery trials as (LCG's) God's will to refine LCG members into righteous persons as pure as gold.
While discussing this topic he mentions his hometown, Pocatello. Even when mentioning a plant in his own hometown he denigrates the American people as being impure and like tarnished dross.
Outside Pocatello, Idaho, the world’s largest elemental phosphorus plant operated before it was shut down in December 2001. It used four massive electric furnaces to refine phosphate ore into a chemical, consuming nearly 15 percent of the state utility’s total electrical output. About 250 megawatts were used to fire up those furnaces.
One of the byproducts of its refining process was molten slag tapped from the furnaces and channeled into waste ponds. It was dross or scum that had to be removed from the elemental phosphorus. It was waste or foreign matter, an impurity.
Because of national sins, God considers His tarnished people dross. He will put them through tremendous heat to refine them and melt away their impurities. (p. 10.)
In September 2006 Mendiola left LCG and joined Dave Pack's Restored Church of God. Around 2008 he left RCG and joined Don Billingsley's Church of God-Faithful Flock.