Do marks in high school matter if I want to go to university after military service?

I just graduated high school with a 70 average for the whole senior year and am now going to serve in the army for 3 years. After my service is done I am looking to pursue a degree in university but I am not sure if I will have to take a year of community college to boost my marks or if good SAT scores and military service will be enough to get me in. Thank you for any information you can give me.