Alisa Petrov, 15, vanished after she was dropped off at her school in the town of American Fork, Utah, about 32 miles south of Salt Lake City, on April 21.
She got off the train in Provo, the end of the line, and asked multiple people to help her get to Las Vegas. The teenager hasn't been seen since.
'Alisa is believed to be attempting to meet individuals she met online using multiple social media platforms and chat applications,' South Jordan Police said.
Those men are allegedly Matthew Nicholas Menard, 35, from Miami and William Taylor Glines, 37, from Texas City, Texas.
Glines was charged with aggravated sexual exploitation of a minor, attempted aggravated exploitation of a minor, sexual exploitation of a minor, enticement of a minor, and criminal solicitation.
Instagram messages between Alisa and Menard going back to January 17, most of which were sexual in nature.
'At one point (Menard) asked (the girl), "Are u secretly 15 lol" to which (she) responded... "of course (y)eppers I'm actually in middle school",' police wrote in charging affidavits.
'[Menard] over the course of several months, corresponded with [the teen] for the purpose of soliciting sex, sodomy, and child sex abuse material from the minor,' it continued.