Earlier this week, Trego mailed out letters to each of the county's 16 local GOP committees announcing he will leave the post by summer's end.
Trego first became involved in politics as a volunteer, working on former Gov. Tom Ridge's re-election campaign in 1998 and President Bush's 2000 campaign.
It was during his volunteer work on the successful prothonotary campaign of former county GOP committee director Randall Wenger that Trego learned the ins and outs of running the party.
"That helped a lot, being able to watch and learn from Randall," Trego said. "There is quite a bit involved in this job."
The extent of his workload was driven home by the 2004 presidential election, when Bush visited Lancaster twice, the second time at Lancaster Airport six days before the election.
"We were working seven days a week at times during that campaign," Trego said. "I think I worked 111 hours in the seven days before the election. We didn't get a whole lot of sleep.
"The ironic thing was, I organized the distribution of 12,000 tickets for (Bush's airport visit), and didn't get to go to the event. I was here at Republican headquarters watching it on TV. In fact, that's the only time the phones were quiet."
Despite all his hard work, Trego is reluctant to take credit for presiding over the largest GOP voter turnout in county history, with nearly 145,000 ballots cast.
"I would say the credit goes to the president for coming here and visiting neighboring counties - York, Chester, Lebanon - with getting voters so enthused," Trego said. "It would be nice to take credit for it, but I don't think it was me."
County Republican Committee chairman David Dumeyer gave Trego high praise, saying his shoes will be hard to fill.
Dumeyer said Trego was key to earning GOP victories, keeping the committee's finances stable and installing a permanent phone bank in the party's Columbia Avenue headquarters.
"He's confirmed all that we believed could happen with the executive director's leadership, but I also thought the same thing when Randall Wenger left," Dumeyer said. "So, you have to move on, but he set the bar up pretty high for whoever is going to come in there."
Trego, who earned a bachelor's degree in education in 1997 from Millersville University, taught economics and government at Hempfield High School for 3 years. When he resigned to take the GOP committee job, the district made no guarantees he would be able to return.
But a friend recently informed Trego that a Hempfield teacher was retiring, and he didn't hesitate to apply. Trego's rehiring is expected to be approved by the school board Tuesday.
"It looks like I'll be back in the classroom in September, and it's almost the same job, except I'll also be teaching advanced-placement government, which is like a first-year college course," Trego said.
Dumeyer, who was a teacher for 15 years in Hempfield School District, understands the call of the classroom.
"One of the things I can tell you, having been in the classroom myself, is, once a teacher, always a teacher," Dumeyer said.
"I think sometimes when you get a chance to pursue something else, as he did and I did, sometimes it is on a short-term basis and sometimes it is long term. I think he still has a love for teaching and can do a lot to mold young minds, so I think it will be great to have him back in the classroom."
Trego said he is excited at the prospect of bringing his experience in gubernatorial and presidential campaigns to Hempfield students, but more than that, he really wants them to understand the importance of local politics.
Because California, which doesn't have townships, is the largest purchaser of textbooks, most government textbooks cover only the federal system, Trego said.
In Pennsylvania, the actions of municipal officials more directly affect residents than federal legislators do, Trego said, but students aren't taught that. As a result, many people grow up uninterested in municipal government, he said.
"We have a mayoral contest and a race for a county court judgeship, but (the May primary) was mainly a primary election for township supervisors, who are very important people," Trego said. "Students aren't getting that in their textbooks, and I hope to bring that to my class."