FORT LEONARD WOOD, Mo. — Fort Leonard Wood’s Marine Corps Detachment marked a new chapter July 17, 2026, bidding farewell to Col. Robyn Mestemacher and welcoming Col. Gideon Grissett as their new commander, during a ceremony held on Gammon Field.
During his remarks, Maj. Gen. Christopher Beck, Maneuver Support Center of Excellence and Fort Leonard Wood commanding general, noted the active role Mestemacher took in leading Fort Leonard Wood’s Marines.
“What is most important about your leadership is you knew when to put your foot on the gas and when to put it on the brake,” Beck said. “You had an incredible sense of your team, you knew what was right for your team, and you delivered for your team.”
He said under Mestemacher’s command, the detachment has been a “great partner” to MSCoE.
“Joint service cooperation has been the story of your time in command here and you have been an incredible teammate,” Beck said. “You have delivered not only for the Marine Corps, but the joint force. It has been a pleasure to serve with you.”
Marine Brig. Gen. Matthew Good, commanding general of U.S. Marine Corps Training Command, echoed those sentiments. Having arrived the day before the ceremony, Good noted, during a tour of Marine training operations at Fort Leonard Wood, that he was impressed by the quality of the "battlespace climate."
“It is a culture and climate built by her and her command team and sustained by her and her team. It was professional and powerfully competent. I felt proud to be a Marine walking around here yesterday,” Good said.
Mestemacher thanked Good for traveling from Quantico, Virginia, to visit the detachment, observe training and preside over the change of command.
“It has been a busy but very good couple of days welcoming you to Fort Leonard Wood for the first time,” Mestemacher said. “It has been great to have you here, sir.”
Mestemacher also expressed her gratitude to Beck, thanking him for his “exceptional leadership.”
“Thank you for reinforcing support for our opportunities to practice as a joint force and for making sure there is always space for the Marines of the Ozarks at the Army’s table,” Mestemacher said.
Hailing from St. Louis, Mestemacher said her time at Fort Leonard Wood was “the honor of a lifetime” and she felt fortunate to be able to conclude her 26-year career so close to home.
“Having the opportunity to command this detachment for the last two years has been the best job I ever had,” Mestemacher said.
“The Marines at this command are magnificent,” she said. “This detachment has no shortage of high performing officers, staff noncommissioned officers, noncommissioned officers, junior Marines, sailors and civilians deeply committed to our mission.”
She said Fort Leonard Wood Marines have made her “proud” every day and they have accomplished “amazing things” in the last two years.
“You have gone above and beyond. You build the future of the Marine Corps here at Fort Leonard Wood,” Mestemacher said.
Turning her remarks to the new commander, Mestemacher said Grissett is stepping into a “disciplined, committed, highly functioning and immensely hardworking organization.”
“I can think of no better officer to take the helm of this command,” Mestemacher said. “If this tour for you turns out to be similar to my own experience, the next two years will go by in a heartbeat. Enjoy every day.”
Good said Grissett’s “breadth of experience” makes her perfect to command Fort Leonard Wood’s Marines.
“You’ve got my complete trust and confidence,” Good said. “Welcome aboard and congratulations.”
Prior to serving at Fort Leonard Wood, Grissett served as a strategic planner and the Campaign and Functional Plans Branch chief in the U.S. Central Command J5 Strategy, Plans and Policy Directorate.
After being on post and watching how the detachment operates over the last two weeks, Grissett said the work the detachment does at Fort Leonard Wood “matters” — to the Marine Corps, the Fort Leonard Wood community and the nation.
“You train hard and you hold a high standard. I have absolutely no doubt that you will continue to do so,” Grissett said. “Fort Leonard Wood is unique. As I look at how we are sharing ranges, classrooms, Interservice Training Review Organization courses, and lessons learned — that kind of proximity builds something that you cannot replicate through message boards or teleconferences.”
She emphasized that when the nation calls upon the joint force, the trust and relationships established at Fort Leonard Wood will provide a critical foundation for cooperative success.
“That is really what excites me about this assignment is the opportunity to contribute to the joint force alignment that happens right here every single day on this installation,” Grissett said. “The better we train them here, together, the stronger that joint force becomes.”
According to Marine Corps Training and Education Command, Fort Leonard Wood’s Marine Corps Detachment is the largest Marine unit on a sister-service installation.
[Marine Corps Detachment Fort Leonard Wood](https://www.trngcmd.marines.mil/Units/Marine-Corps-Detachment-Fort-Leonard-Wood/) trains Marines in 18 military occupational specialties in the areas of motor transportation, military police, engineer equipment, chemical, biological, radiological and nuclear defense, and is also the home the Non-lethal Individual Weapons Instructor Course.
More photos from the ceremony are available to view and download in this [Fort Leonard Wood photo album](https://flic.kr/s/aHBqjCZfX2).