SEATTLE – The Army is in the early stages of establishing a third Stryker brigade at Fort Lewis as it nears its goal of creating seven of the units named for the eight-wheeled armored vehicles.

About 200 senior leadership members for the newly named 5th Brigade, 2nd Infantry Division have been arriving at the Army post south of Tacoma since September, said Joseph Piek, a spokesman for the post.

The completion of the new brigade will realize the Army’s goal of creating seven of the combat teams to serve as medium-weight, rapidly deployable units to fill the gap between lighter infantry and heavy forces. Four other brigades are in Alaska, Hawaii, Pennsylvania and Germany.

The 5th Brigade joins two other Stryker Brigade Combat teams stationed at Fort Lewis, the 3rd and 4th brigades.

Previously, Fort Lewis had been home to the 1st Brigade, 25th Infantry Division, another Stryker team that earlier this year was renamed the 2nd Cavalry Regiment and transferred to Germany as part of the Army’s reorganization.

Currently the 3rd Brigade – the Army’s first Stryker team – is on its second yearlong tour in Iraq, a mission that is scheduled to end in summer. Members of the brigade now in Mosul are expected to be moved into Baghdad to help shore up security there, Pentagon officials said this week.

The 4th Brigade is training at Fort Lewis as it prepares for an Iraq deployment next year. On Monday, the unit will begin 10 days of field exercises as a precursor to training at the National Training Center in Fort Irwin, Calif., where it will prepare for combat in a desert setting and receive its deployment certification.

Meanwhile, battalion and company leaders with the 5th Brigade are settling in at the post and seeing to headquarters arrangements, including acquiring barracks and motor pools.

“We’ve got to have all of that infrastructure in place before the majority of the soldiers get here,” Piek said.

The brigade will be made up of soldiers throughout the Army, some with previous experience in a Stryker brigade, Piek said. Fort Lewis officials expect several hundred to begin arriving in January, followed by a group of roughly 1,000 each in February and March. By June or July, the unit will be complete with about 3,800 soldiers.

The 300, 19-ton armored Stryker vehicles and hundreds of other support vehicles will start arriving after the first of the year.

“They will be able to start their training cycle by the end of next year,” Piek said.

Once the 5th Brigade is in place, Fort Lewis’ active-duty population will top 31,000, Piek said.

He noted there are typically only four infantry brigades in a division and that the latest brigade will eventually be renamed the 2nd Brigade, 2nd Infantry Division to replace one currently at Fort Carson, Colo. That brigade, he said, will be inactivated by December 2007. The 1st Brigade is based in Korea.