The Purgatoire River is a river in southeastern Colorado, United States. "Riverine" redirects here For the use of that term in Maritime geography, see there The State of Colorado ( or chiefly by nonresidents) is a state located in the Rocky Mountain region of the United States of America. The United States of America —commonly referred to as the The river is also known locally as the Picketwire River. The Purgatoire River originates at the confluence of the North Fork Purgatoire River and Middle Fork Purgatoire River near Weston in Las Animas County, Colorado, and flows generally east-northeastward approximately 282 kilometers (175 mi) to its confluence with the Arkansas River at John Martin Reservoir near Las Animas in Bent County, Colorado. Weston is an unincorporated Town and a US Post Office located in Las Animas County, Colorado, United States. Las Animas County is the largest of the 64 counties of the State of Colorado of the United States. The City of Las Animas is a Statutory City that is the County seat of and the only incorporated municipality in Bent County, Colorado Bent County is one of the 64 counties of the State of Colorado of the United States. The Purgatoire River drains an area of 8923 square kilometers (3445 sq mi) including 8601 square kilometers (3321 sq mi or 96. 4%) in Colorado and 321 square kilometers (124 sq mi or 3. The State of Colorado ( or chiefly by nonresidents) is a state located in the Rocky Mountain region of the United States of America. 6%) in New Mexico. New Mexico ( is a state located in the southwestern region of the United States of America. [1]