[7] With the 25 June 1950 outbreak of the Korean War, the North Korean People's Army had invaded the Republic of Korea (ROK) with 90,000 well-trained and equipped troops who had easily overrun the smaller and more poorly equipped Republic of Korea Army.

[10] At the same time, North Korean agents began to infiltrate behind UN lines and attack military targets and cities.

North Korean special forces units like the NK 766th Independent Infantry Regiment had seen great success in defeating ROK troops,[3][12] prompting Army Chief of Staff general J. Lawton Collins to order the creation of an elite force which could "infiltrate through enemy lines and attack command posts, artillery, tank parks, and key communications centers or facilities.

"[1] All U.S. Army Ranger units had been disbanded after World War II because they required time-consuming training, specialization, and expensive equipment.

[15] The Rangers trained extensively in reconnaissance, long-range patrols, motorized scouting, setting uproadblocks, land navigation, camouflage, concealment, and adjusting indirect fire.

[6] The 1st Ranger Company undertook equipping in Sasebo, Japan before arriving in Pusan, South Korea where they were trucked to the 2nd Infantry Division on 23 December, where they would be attached.

The 2nd Infantry Division, which was south of Seoul, had been badly mauled in the Battle of the Ch'ongch'on River earlier in the month, and were rebuilding.

Striegel contracted severe hepatitis and was evacuated, replaced on 6 January 1951 by Lieutenant Alfred Herman, his executive officer.

As the bitter cold and snow hampered actions around Wonju, the Rangers were also employed as forward observers and snipers, as their nighttime movement was limited.

[15] On 16 January the company conducted its first mission as a single unit, a probe north of the front lines to scout Chinese positions.