Idaho saw virtually no combat during the Civil War. It is so far removed and remote that there were never any Confederate forces in Idaho at all.
The only event that took place during the Civil War was a fight between Native Americans and Union forces in 1863.
This clash began after several Indian raids occurred and the Union decided to put a stop to them.
This fight turned into a massacre as Union forces killed almost all of the Native American warriors and many women and children.
The following are all Civil War battles in Idaho although there is only one that took place.
Other Names: Massacre at Boa Ogoi
Location: Franklin County
Campaign: Expedition from Camp Douglas, Utah Territory, to Cache Valley, Idaho Territory (1863)
Date(s): January 29, 1863
Principal Commanders: Col. Patrick Edward Connor [US]; Chief Bear Hunter [I]
Forces Engaged: District of Utah [US]; Shoshoni Indians [I]
Estimated Casualties: 451 total (US 67; I 384)
Description: Shoshoni raids under Chief Bear Hunter during the winter of 1862-63 provoked Federal retaliation. Troops under Col. Patrick E. Connor set out from Ft. Douglas, Utah, in the deep snow of January 1863 towards Chief Bear Hunter’s camp, 120 miles north near present-day Preston, Idaho. The Native American camp included about 300 Shoshoni warriors defensively placed in the Battle Creek ravine west of Bear River with high embankments in which the Indians had cut access trails. Shortly after dawn on January 29, Connor’s troops appeared across the river and began crossing. Before all of the men had crossed and Connor had arrived, some troops made an unsuccessful frontal attack which the Indians easily repulsed inflicting numerous casualties. When Connor took over, he sent troops to where the ravine debouched through the bluffs. Some of these men covered the mouth of the ravine to prevent any escape while others moved down the rims, firing on the Indians below. This fire killed many of the warriors, but some attempted to escape by swimming the icy river where other troops shot them. The battle stopped by mid-morning. The troopers had killed most of the warriors plus a number of women, children and old men and captured many of the women and children.
Result(s): Union victory (massacre)
Source: https://www.nps.gov/civilwar/search-battles.htm# No protection is claimed in original U.S. Government works