FORT McCOY, Wis. -- For Sgt. Dustin Crotinger, days during the Combat Support Training Exercise are so long, they often don't end until tomorrow.

"I was out until 2 a.m. last night, which can be kind of typical," said Crotinger, a transportation specialist with the 232nd Base Support Battalion who is attached to First Army for the CSTX. "Being an observer coach/trainer, we're there until the training is done. We train to standard, not time. But that's my favorite part of this, just being out with the troops and being able to see their improvement during their time out here."

This month, thousands of Soldiers are taking part in the CSTX, which is designed to assist combat service and combat service support units in planning, preparing, supervising and executing pre-mobilization during a collective training event.

First Army Soldiers are serving as OC/Ts, a role that has them helping to guide the units to achieve their commanders' training objectives. It usually makes for long but productive days, like the ones Crotinger puts in.

"It's a lot of work, but it's great to be able to … help Soldiers train so that they are ready to go overseas and defend our country," Crotinger said. "For an OC/T, the key is being organized and knowing the doctrine of the unit you're working with."

As their title says, OC/Ts observe, coach, and train, and also work with their counterparts' subject matter experts, said Capt. Michael Rear, an OC/T with First Army Division West's 4th Cavalry Brigade.

"We are here so the units can better pinpoint and identify some of the difficulties they are having and try to give them a way ahead and steer them so they can better figure out what mission they should be doing and help guide them in the right direction."

Rear stressed that the OC/T's role is leading the units to self-awareness. "The key is letting them discover their own mistakes and strengths. We don't dictate to them or critique them," he said. "We don't say, 'Hey, you messed up.' Rather, we will add our input, and eventually they will realize what they did well or where they need work. They will learn themselves what they need to work on."

"Some of the units in the CSTX are in their Preparation Year Three, meaning this is the year before they go into their final evaluation to prepare for their available year," said Command Sgt. Maj. Jeffrey Dillingham, First Army Division West's senior enlisted Soldier. "So we task-organized across each organization so we could best support them and meet their commanders' needs in their deployment requirements."

OC/Ts consider where units are in the readiness cycle, he added.

"There are different units at different levels," Dillingham said. "Not all of them are at the same point in the readiness cycle. We have an MP unit out here that is going to deploy next year, so we are trying to mirror this training event to their real-world mission and set them up for their final validation."

But, according to Dillingham, wherever a unit is in the readiness cycle, the keys for First Army include being flexible and continually learning.

"Every unit has a different wartime mission and commander's training objective," he said. "Between our First Army Academy, and being continually trained on how to provide feedback and facilitate After Action Reviews, and finding subject matter experts to work with, we can help set the units up for success. And if we do that, it makes us successful."

The Soldiers going through the CSTX report that First Army is indeed helping the units achieve their goals.

"There are long days because there a lot of different training requirements and benchmarks to meet," said Spc. Jose Vicencio, a welder with the Army Reserve's 950th Support Maintenance Company from Los Alamitos, California. "And the OC/Ts are helping with that. They are knowledgeable about what they are doing, and they don't tell us what to do. They ask questions that help us assess what our best course of action might be, but they don't dictate anything. They are very helpful."

Agreed, says Cadet Kekupafa Pratt from the University of New Mexico.

"It's been a very good learning experience. The OC/Ts have been extremely helpful," he said. "It's been a lot more than just as assessment that you pass or you failed. They really help us drill down and recognize and correct the deficiencies. And by doing that, we get a lot more training value out of it."

For Spc. Breanna Jones, a supply specialist with the Army Reserve's 639th Transportation Company from Bedford, Virginia, that level of specificity makes the CSTX more challenging, but also more rewarding.

"The OC/Ts have some detailed, complex questions, but I like that because it forces us to think about what we're doing out here, and what our mission is, and what we're supposed to be taking away from this," Jones said.

It's all paying off, she added. "I've learned a lot more out here than I've gotten in any of my other training."