year, a peace treaty was signed. However, in the 1850s tensions grew between the Achomawi and the Modoc, leading to armed conflicts that continued for over twenty years. Despite multiple attempts by leaders on both sides to make peace, "each time the truce was soon broken by irresponsible young fellows whom the chiefs could not control." Conflict with Europeans Native peoples also grew hostile towards Euro-American settlers and traders, who entered the region in great numbers beginning in the mid-19th century, especially during and after the California Gold Rush in 1848. There was little conflict at first with outsiders who were just passing through the area on their way to the Sacramento Valley. However, after white Americans settled near Fall River, conflict broke out. After initial skirmishes, soldiers led by US general George Crook arrived in the area. The natives negotiated a temporary truce with Crook, in the form of a gift of a large number of furs. This was broken the next year, when two settlers were killed by Atsugewi for an unknown reason. In retaliation, a band of white men attacked a native camp at Beaver Creek (near present-day Pittville) killing 160 people, mostly women and children. The military Pitt River Expeditions against local Indian Tribes occurred during the 1850s. The first expedition in 1850 was mainly an attempt to establish better relations with the indigenous peoples. The second, led by General Crook in 1857, was a military engagement, as the US government decided to forcibly remove the Pit River natives and move them to the Mendocino Indian Reservation (then later the Round Valley Indian Reservation) in Mendocino County. The former enemies of the Achomawi – the Modocs and Klamaths – were also driven out of the region by 1873 with the conclusion of the Modoc War. This is considered to be the point at which the Pit River valley was opened up to large-scale White settlement. Irrigation and power Due to the arid climate, poor soils and rugged topography of the Pit River basin and northeastern California in general, settlement and development of the region was difficult. Ranching became the primary economic activity, thanks to the expansive seasonal grasslands, along with some mining and logging. Although the lower portions of the Pit River contain abundant water, the western watershed is too mountainous for agriculture. On the other hand, the drier eastern part of the watershed contains a