One of the most significant developments connected with Birch Coulee was that Colonel Sibley left a message for Little Crow – enclosed in a cigar box and attached to a stake in the ground – on the battlefield afterwards, knowing it was likely to be found. In his letter, Sibley wrote, "If Little Crow has any propositions to make, let him send a half-breed to me, and he shall be protected in and out of my camp," opening a series of communications between Sibley and Little Crow (and, unbeknownst to Little Crow, between Sibley and a few disgruntled Mdewakanton chiefs). In his subsequent letters, Sibley urged the release of the prisoners as a prerequisite for any negotiations – a condition Little Crow was unwilling to accept.
