Given the task definition and input, reply with output. In this task, you're given a statement, further information available on a particular linked term from the statement, and a question. Your job is to generate the answer to the question by using the information provided. If there is no clear answer obtainable, output 'none'.

Context: On 1 June 1937, the 12th Observation Squadron left Texas to operate with the 7th Cavalry Brigade, the mechanized forerunner of the First Armored Division, at Fort Knox, Kentucky. While stationed at Fort Knox, the squadron participated in field maneuvers with the mechanized cavalry near Fort Oglethorpe, Georgia, and at Fort Riley, Kansas Link Information: .

The depository was built by the Treasury in 1936 on land transferred to it from Fort Knox. Question: Of the forts that participated in field maneuvers in 1937, which was the oldest?
Answer: Fort Riley