On December 31, 1870 Bvt. Lt. Colonel Rice was assigned to the 5th U.S. Infantry under the command of Colonel Nelson A. Miles. He was on duty at Fort Wilas and Fort Leavenworth, Kansas until December 1873.  He was ordered to the Springfield Mass. Armory in Dec. 1873, where he superintented the manufacture of 10,000 of the Rice Trowel Bayonets and the Rice Stacking Swivel, his own inventions which were to be used by the U.S. Army, Navy and Militia.

He returned to the west and commanded the expedition against the Ute Indians in July, 1874 near the Spanish Peaks, Colorado.

In 1875 he reorganized the United States Military Prison at Ft. Leavenworth and was in command of the prison until July 12, 1876, when he was relieved at his own request to join his regiment in the campaign against the hostile Sioux which had recently wiped out Gen. Custer and his 7th Cavalry.

In August , 1876 he was ordered to take flat boats and one three inch rifled gun and 75 men of the 5th Infantry and proceed from the mouth of the Powder River down the Yellowstone River, Montana in search of the hostile Indians. When opposite the mouth of Glendive Creek, he and his men landed and threw up field fortifications with their Rice Trowel Bayonets. They were attacked by a large party of Sioux who were driven off by a few rounds fired from the rifled field gun. Rice and his troops remained at this post until they were relieved by additional troops of Colonel Miles command.

In February of 1878 he was placed in command of two hundred men with 35 wagons and proceeded from Bismarck, Dakota Territory, up the east bank of the Missouri River and the north bank of the Yellowstone River, through the Dakota and Montana Territories. They marched through the heavy snow for 430 miles until they reached their destination at Fort Keough in April 1878.

In July of 1878 Rice commanded the six gun battery in Colonel Miles expedition against the Sioux, north of the Missouri River near the Canadian Border.He took part in the engagement on July 17th and was the first to use the revolving Hotchkiss cannon in action on this continent.

Rice was recommended for brevet colonel U.S. Army and served as adjudent of the 5th Infantry and assistant adjudant-general, district of the Yellowstone from July of 1879 until March of 1883.

He was again on duty at Fort Leavenworth, Kansas from November of 1883 through September of 1885. He was then transferred back to Fort Keough from September of 1885 until August 1886, and then to Fort Totten, Dakota Territory until April of 1888. From 1888 through 1891 Edmund Rice was stationed in Texas at Fort McIntosh, Fort Bliss and finally in command of Fort Hancock.