• In October 1969, General Singlaub was ordered to Fort Hood, Texas, to help establish the new, high-priority test and evaluation facility known as Project MASSTER (Modern Army Selected Systems Test, Evaluation and Review). He served as the Chief of Staff of that Project until June 1971. While assigned to Project MASSTER, General Singlaub engaged in Army flight training and became a qualified rotary wing aviator.

• General Singlaub was assigned in June 1971 as the Director of Plans, Studies and Budget, Office of Deputy Chief of Staff and Personnel, Department of the Army, Washington, D.C., where he remained until September 1971.

• On 21 September 1971, General Singlaub was appointed as the Deputy Assistant Secretary of Defense for Drug and Alcohol Abuse, OASD (H&E). He remained in this position until August 1973.

• On 6 August 1973, General Singlaub was appointed as the Commander, US Army Readiness Region VIII (USARR VIII) located at Rocky Mountain Arsenal, Denver, Colorado. Subsequently, on 20 November 1974, his command was relocated to a newly renovated headquarters at Fitzsimons Army Medical Center, where he served until June 1976.