 Kọ ìlọsíwájú fún ìpínrọ yìí - Grange ni wọn yàn gẹgẹ bí òṣìṣẹ ọmọ ogun abẹlé ní December 1969. Grange kọkọ rí ìgbésẹ ìjà tí ó ṣe pàtàkì gẹgẹ bí ọgágun kejì tí a yàn sí ẹgbẹ 101st Airbornes Lima Ranger company ní I Corps Tactical Zone of Vietnam ní 1970. Ẹgbẹ yìí jẹ ara Ẹgbẹ ọmọ ogun ẹlẹẹdẹgbẹrin Ranger tí wọn sì so mọ Ẹgbẹ ọmọ ogun ẹlẹṣin 217th. Gege bi alaga agba akọkọ ti o ṣiṣẹ ni irin-ajo keji ni Vietnam lati 1971 si 1972, Grange jẹ onimọran si Ẹgbẹ-ogun ti Orilẹ-ede Vietnam Airborne. Grange ni a fun ni ọpọlọpọ awọn ẹbun Silver Star fun igboya ni Vietnam pẹlu ẹbun rẹ kẹta fun igboya ni iṣe ni Kínní 1972 lakoko ti o n ṣiṣẹ pẹlu Ẹgbẹ Onimọran Airborne ti AMẸRIKA. Grange pada si Fort Bragg ni 1972 o si ṣiṣẹ pẹlu 3rd Battalion, 5th Special Forces Group gẹgẹbi olori oludari ati olori oludari titi di ọdun 1974. Ni ọdun yẹn, Grange pari ikẹkọ Flight ati lẹhinna ṣiṣẹ pẹlu Ẹgbẹ-ogun 158th Aviation. Lati Oṣu Keje ọdun 1978 si 1980, Grange ṣiṣẹ bi olori ile-iṣẹ ọmọ-ogun, C Company, 1st Ranger Battalion, 75th Ranger Regiment, eyiti o ṣe atilẹyin Iṣẹ-ṣiṣe Eagle Claw ni Oṣu Kẹrin ọdun 1980. Ní ọdún 1981 Grange parí ìdánilẹkọọ British SAS Course ní Hereford, England lẹyìn náà ó lọ sí ilé ẹkọ Command and Staff College ti Marine Corps. Ni 1982, Grange ṣe onisẹfẹ fun ati gba iṣẹ-ṣiṣe si 1st Special Forces Operational Detachment  Delta 1st SFOD-D, tabi Delta Force ni Fort Bragg, North Carolina. Grange ṣe olori B Squadron nigba ikọlu ti Grenada ni Oṣu Kẹwa ọdun 1983 ti o tẹle pẹlu iṣẹ bi oṣiṣẹ iṣiṣẹ iṣiṣẹ. Ni ọdun 1987 Grange ṣe onisẹfẹ fun iṣẹ ni South Korea o si gba aṣẹ ti Batalionu 1, 503rd Infantry Regiment, 2nd Infantry Division titi di ọdun 1988. Lẹyìn náà ni wọn yàn án gẹgẹ bí òṣìṣẹ àkànṣe-iṣẹ ní Special Operations Command, Washington, D.C. ní 1989. Grange lọ si Ile-ẹkọ Ogun ti Orilẹ-ede ati pada si Fort Bragg ni Oṣu Karun ọdun 1990 gẹgẹbi igbakeji olori ti Delta Force, ninu iṣẹ ti o paṣẹ fun ẹgbẹ iṣẹ-ṣiṣe kan lakoko Igba Irẹdanu Ewe : ó ṣe tán. 