The Battle of the Ivanov Trail was a skirmish between the Spanish and Russian settlers of present-day Humboldt County, California which occurred along the "Ivanov Trail" travois route in 1818.
The Russian settlers of Alaska had established Fort Ross in northern California in 1818, aiming to establish trade with the Native Americans and compete with the Spanish settlers of Alta California, who had pushed up to the San Francisco Bay Area and established a presidio there to guard against further Russian expansion. Tensions rose when the Spanish and Russians each founded small colonies along a Native American travois route in present-day Humboldt County, with the Spanish founding Bosque Miranda in the south and the Russians founding New Donetsk in the north. The two empires established trading posts along the route, which the Russians named the "Ivanov Trail" after the founder of a Russian trading post. After discovering that the Spanish had already established trading posts along much of the route, the Russians decided to mobilize troops to destroy the Spanish trading posts and protect their colony's interests. The Russian soldiers Timofey V. Dudko, Yuliy V. Dyogtin, Vaniamin Y. Glagolev, Foma S. Sharonov, and Zhenka T. Siyangulov travelled southwest, where they came across a Klamath village where the Spanish had established a trading post. The Russians began to torch the trading post, but the Spanish had prepared a large garrison of their own, and this garrison killed the Russian interlopers.
Shortly after, the Spanish prepared their own expedition, which followed the route of the Russian soldiers along the coast. Another Spanish force, consisting of hired Comancheros and renegados, marched inland to protect the Spanish trade routes, and it entered into a heated battle with a sizable Russian force which had marched south to burn the Spanish trading posts. The mercenaries were later reinforced by the rest of the Spanish expedition, which included mounted lancers and a large number of Nootka and Klamath mercenaries. This larger Spanish and Native force overwhelmed and massacred the Russians, pursuing their remnants to their colony of New Donetsk, which they proceeded to destroy.