It needed to make the trail unusable and the forts unsustainable at a cost the U.S. government was unwilling to continue paying.

That is exactly what it did.

The total number of military engagements during Red Cloud’s War — small skirmishes, larger fights, attacks on supply trains and work parties — numbered in the hundreds over the two-year campaign.

Most of them were individually inconclusive.

Collectively, they constituted a sustained campaign of attrition that the Army could not effectively counter.

The Army’s options were limited.

It could increase the garrisons — but the additional soldiers needed supplies, and those supply lines were themselves under attack.