Monument is a city in Grant County, Oregon, United States. The population was 128 at the 2010 census. It is located close the confluence of the North and Middle Forks of the John Day River. Its make known office was established in 1874 and named for a open mountain or stone formation.

As of 2000, the Monument School District, consisting of the Monument School, had a 7,000-square-foot (650 m) science building for its environmental sciences curriculum, which was paid for by a federal comply of approximately a $500,000. The program taught students more or less the ecology of local Ponderosa Pine reforest and sagebrush steppe and the water mood and domicile of streams. The intellectual had higher than 100 students in 1997, but the decrease of ranching and timber production caused many families to move, bringing the number of kids at the scholarly down to 62 by the year 2000. Annual federal timber payments to the city of Monument declined from $100,000 in 1990 to $5,000 in 2000. With a population of 165 in 2000, Monument had “a grocery store, restaurant, tavern, three churches, a senior center, fire station and the offices of the Columbia Power Electric Cooperative utility.”

According to the United States Census Bureau, the city has a total Place of 0.51 square miles (1.32 km), all land. By road, Monument is 110 miles (180 km) southwest of Pendleton, about 64 miles (103 km) northwest of John Day, and about 156 miles (251 km) northeast of Bend.

This region experiences warm (but not hot) and teetotal summers, with no average monthly temperatures above 71.6 °F (22.0 °C). According to the Köppen Climate Classification system, Monument has a steppe climate, abbreviated “BSk” on climate maps. An average of nearly 13 inches (330 mm) of precipitation falls on Monument each year.