Some more info.
COMBAT FAILURE: NIGHTMARE OF ARMORED UNITS SINCE WORLD WAR II - A Monograph by Major William R. Moyer, page 33.
http://cgsc.contentdm.oclc.org/cdm/sing ... 587/rec/61"There were very few tank battles in Korea. Like Italy in World War II, the terrain of the Korean peninsula did not support large armored operations. In addition, even though North Korean T-34 tanks led the attack south of the 38th Parallel, the 400 or so tanks of the North Korean Peoples Army were knocked out of action by early winter, 1951. After that, the only significant threat to US armor were minefields and sporadic bazooka fire. In fact, the only serious defeat of American armor in Korea came when a tank column was ambushed by Chinese infantry in a narrow pass between Kunu-ri and Sunchon. In the engagement, sixteen tanks were attacked and destroyed. The largest recorded tank battle of the war occurred in November 1950, when one US tank company took on and defeated a company of North Korean T-34's.
"Constricted terrain and road networks laced with mines proved to be the major threat to US armor in Korea. Effective maneuver was next to impossible throughout the theater due to the poor roads. As a result of poor terrain, armored battalions were reduced in effectiveness and largely supported dismounted infantry action. This infantry support mission and intermittent use as indirect fire in place of artillery, tied up the efforts of most of the tank outfits in theater. A 1st Cavalry Division after action report made clear that "enemy North Korean tanks showed reluctance to slug it out with the medium tanks in tank versus tank fights." (76) Armored unit failure usually only occurred as a result of friendly errors: tank units failing to properly clear minefields, or carelessly entering dangerous chokepoints without an infantry escort."(76) "Employment of Armor in Korea, Volume II," Operations Research Office, 8th Army, Korea, 8 Aug 1951, p. 218.
I cannot find a clean version of Reference 76 on the web. My anti-virus software goes ballistic and won't allow me to open the documents. Volume I is readily available at the CGSC website.
As an aside, Moyer's paper also discusses the disaster at Sidi-bou-Zid, Tunisia where we lost 100 tanks and an infantry regiment.