The Battle of Lost River was a battle in the United States Modoc War.

Despairing of a peaceful settlement, on November 27, Superintendent Odeneal requested Major John Green, commanding officer at Fort Klamath, to furnish sufficient troops to compel Captain Jack to move to the reservation. On November 28 Captain James Jackson, commanding 40 troops, left Fort Klamath for Captain Jack's camp on Lost River. The troops, reenforced by citizens from Linkville (now Klamath Falls, Oregon) arrived in Jack's camp on Lost River about a mile above Emigrant Crossing (now Stone Bridge, Oregon) on November 29.

Wishing to avoid conflict, Captain Jack agreed to go to the reservation, but the situation became tense when Captain Jackson demanded he disarm. Captain Jack had never fought the Army, and was incensed at this command, but finaly aggreed to put down his weapons.

As the rest of the Modoc were following his lead, it is believed that the Modoc warrior Scarfaced Charley and an unidentified Army sergeant got into a verbal argument, pulled their revolvers and shot at each other, both missing their target. The Modoc scrambled to regain their recently cast aside weapons, and fought a short battle before fleeing towords the border with California. After driving the Modoc from camp, Captain Jackson ordered the troops to retreat to await reinforcements. The casualties in this short battle included one Army soldier killed and seven wounded, and two Modoc killed and three wounded.

Retreating from the battlefield on Lost River to the Lava Beds south of Tule Lake, a small band of Modoc under the leadership of Hooker Jim, on the afternoon of November 29 and morning of November 30, killed 18 settlers.