On April 4, 1862, the battalion was ordered to St Louis, Missouri, and during the month of May, marched to Fort Laramie in the Idaho Territory, a prominent post along the Oregon Trail.
The battalion located its headquarters at Pacific Springs, Nebraska Territory, assigned to protect travelers and interests along the North Platte and Sweetwater Rivers, and then at South Pass, Idaho Territory, to guard the Overland Mail routes from Julesburg, Colorado, to Green River, Wyoming.
The additional four companies were activated as a defense against Morgan's Raid in July before being sent to Fort Leavenworth, Kansas, at the start of August.
The battalion and later the regiment were stationed in the Idaho Territory to replace the regular troops who had been posted there before the Civil War.
Upon arrival at Fort Laramie, the troops were assigned to various posts along the Sweetwater and North Platte Rivers between Nebraska and South Pass.
Most fought their way back to the bridge, held by a 20-man support force of the 11th Ohio and Company I, 3rd U.S. Volunteer Infantry en route to Fort Laramie, but six were cut off and killed, including Collins.
In August, Companies E and K from Fort Laramie accompanied Colonel James H. Kidd's western column of Brigadier General Patrick E. Connor's Powder River Expedition aimed at stopping Sioux, Cheyenne, and Arapaho attacks on the Bozeman Trail.
Sergeant Charles L. Thomas, Company E - Medal of Honor recipient for heroism during the Powder River Expedition In 1957, the Troopers Drum and Bugle Corps was founded in Casper, Wyoming.