After 30 years of service within the Capitol Police Department, Assistant Chief James Rohan announced Thursday that he will step down at the end of the month to become director of security for The Greenbrier Resort.

The famed resort, located in White Sulphur Springs, W.Va., has a number of Capitol Hill connections. Not only is it the site of several Congressional retreats each year, but from 1956 to 1962, an enormous bomb shelter meant to house Congress in the event of a nuclear strike was built under a wing of the resort’s main hotel. The facility was custom-built to meet the requirements of a Congress-in-hiding, complete with chambers for both the House and the Senate, a hall for joint sessions, and space for more than 500 staffers. Its existence was declassified by the Defense Department in 1995, and the resort now offers tours of the bunker.

Rohan will replace Bob Wanko, a former Secret Service agent who worked on the presidential detail, when he starts his new job Nov. 27.

An internal selection process for the next assistant chief is ongoing, and Rohan said one of the department’s four deputy chiefs — Christopher McGaffin, Vickie Frye, Larry Thompson or Michael Jarbo — will be tapped to fill his shoes.

In an announcement issued last week, Capitol Police Chief Terrence Gainer said Rohan’s “extensive knowledge of the Department structure and the operations of Congress has proved to be vital in assessing the needs of security on Capitol Hill. … After 30 years of dedicated service, we’ll have some big shoes to fill. He will truly be missed.”

“Thirty years is a heck of a milestone, I think, in any law enforcement career. It’s certainly a milestone in being able to serve the legislative branch,” Rohan said in an interview Friday.

Rohan has served the Capitol Police through eight inaugurations and all six chiefs (the position was created in the late 1970s) since joining the force’s Senate Division in 1975.

“I think we’ve made some dramatic changes to increase the security of this place since I’ve been here, and I’ve just been privileged to be a part of that,” he said.

When Rohan began working for the Capitol Police, the entire department had only six bomb-sniffing dogs and performed little more than visual checks on visitors to the Capitol. These days, the department has somewhere in the area of 50 K-9s, and Rohan has helped oversee the creation of such units as the Hazardous Materials Response Team and the Containment and Emergency Response Team in his roles as Operations Services Bureau commander and Uniformed Services Bureau commander.

Rohan said that along with the people he’s worked with, witnessing historic events on a daily basis is what he’ll miss the most.

“It’s the involvement in history,” he said. “I oversaw all the security for the impeachment. … I was here when they took the statue down off the Dome to restore it. That’s another one of those things they only do every couple hundred years.”

Rohan said the challenge facing the Capitol Police as he leaves is to keep pace with emerging threats and keep Congress safe while at the same time keeping the legislative branch as accessible as possible.

“Some of those are conflicting challenges … [but] we’ve had very few incidents where we had to evacuate the whole place. Most of the time we’re pretty darn good about giving the best response available, and the best assessment available and the best resolution available and Congress can still function while we’re doing it. That’s all done without any fences up here. That’s our job.”

On Friday, Capitol Police Labor Committee Chairman Andy Maybo wrote in an e-mail that “Chief Rohan was a great Assistant Chief for the USCP officers. His leadership and professionalism will be greatly missed. We wish him the best of luck for the future and we hope he leaves knowing his shoes will be difficult to fill.”