The letter goes on to thank his fellow Streets Department workers, residents and contractors. Gilman also thanked Alderman Tom Gleason "for his lifelong commitment to the city... and his support during my tenure as Street Superintendent." Gilman also thanked Alderman Steve Sauer for "his common-sense approach and dedication to representing the people and not his own agenda."
Both Sauer and Gleason declined to comment for this story.
Gilman dedicated 19 years to serving his hometown of Rhinelander, joining the Public Works Department in October 1997. He became streets superintendent in 2013.
"I was born and raised in the house that sits 200 feet from my current home," Gilman told Newswatch 12 over the phone Tuesday afternoon. "I've always loved this place."
Gilman wouldn't elaborate on any specific complaints he had with leadership. However, his letter goes on to say, "I believe any community, including Rhinelander, can only reach its potential with positive efforts towards teamwork, proper leadership in place, and accountability by its staff. Unfortunately, I believe those qualities to be lacking by some within our organization."
Gilman noted his concerns might not be shared by others in the city or the Public Works Department.
"Just because I have a certain perception of problems, it doesn't mean everyone agrees," Gilman said over the phone.
The news took Mayor Johns by surprise.
"It's going to be a loss for the city," Johns told Newswatch 12 Tuesday morning. "In my opinion, [Gilman] did an excellent job for the city."
Gilman's is just the latest in a series of departures by city employees.
The Council effectively fired City Administrator Kristina Aschenbrenner in August 2016, a little less than one year after she was hired. Police Chief Mike Steffes resigned in the middle of October, after spending nearly 10 years with the city, to take a job with the state Department of Justice. The Police and Fire Commission's chosen successor for Steffes, Kiel Police Chief Dave Funkhouser, initially agreed to take the job, then backed out after contract negotiations soured.
City Administrator Assistant Kathy Johnson also announced her retirement this spring.
Gilman's resignation letter, though, offered some of the more pointed reasons for departure compared to any other former employees of late.
"You'd better believe it, I'm concerned about that, yes," Johns said in response to Gilman's letter.
Alderman Alex Young chose to not comment directly on Gilman's departure. But Young issued his own letter to Johns and Alderman Mark Pelletier late Tuesday afternoon.
"In a December, 2016 Finance, Wage, & Salary committee meeting, Mayor Johns publically announced that he had received 'another complaint' (presumably in addition to several others), related to Public Works personnel including a department head and which apparently related to personnel problems and concerns in those departments (Public Works, the Water Utility, and the Wastewater Utility)," Young wrote.
"I was told then, probably rightfully, that it was not the City Council's business to get directly involved, but that it was more appropriate for the Mayor as the Chief Executive Officer of the City (as provided by state law), the City's insurance carrier, and City staff to deal with whatever the pending complaints or issues referred to by the Mayor may be... However, nearly six months have passed since then without an update to the City Council or the committee.
"Given recent events including the resignation of Mr. Gilman, it is apparent to me that whatever lead to those complaints has continued to be a problem for the City... it nevertheless appears to me that if these issues continue to be unresolved, that at some point the City Council deserves to know what is going on and why, and to have a full update from the Mayor and staff."
Gilman's boss, Public Works Director Tim Kingman, offered a limited response to the resignation letter.
"I just wish Tony the best," Kingman told Newswatch 12. "He won't be easily replaced."
Gilman's job as streets superintendent in Baraboo will be largely similar to his current job of the same title in Rhinelander.
"He was one of the more experienced candidates," Baraboo City Administrator Ed Geick told Newswatch 12. "But it wasn't as much his experience but rather his experience and personality. Tony fit the criteria we had."
Gilman will supervise about 15 employees in street, stormwater, garbage pickup, and recycling areas, according to Geick.
"We're a very welcoming community," Geick said of Baraboo. "I think that Tony will find that he will not have any trouble fitting in and finding a place to stay and getting involved."
Gilman says Baraboo offers a very strong "team-oriented" group of city workers.
"It was tough to say goodbye [to my crew] this morning," Gilman said. "I'm so proud of our crew here. They're so reliable.
"My whole family (which includes a wife and two daughters) is excited to get down to Baraboo. With me taking this role, it's a good move for my family."
Gilman's last day on duty with Rhinelander was Tuesday. He'll technically be a city employee until June 2. Gilman begins his new job in Baraboo on June 19.