Ernest Calvin Baxter was born in Steuben County, New York, on May 3, 1870, and grew up on his father's farm near Nelson, Pennsylvania. In July 1893 Baxter traveled to Montana, working for a time as a bookkeeper at the Crow Indian Agency before investing in a chain of mercantile stores located in the Twodot area. It was in Twodot that Baxter met Clarence P. Tooley who became a close business associate.

Beginning in 1905 Baxter and Tooley formed two ranching businesses; the Twodot Land and Livestock Company and the Tooley-Baxter Land and Livestock Company. Together these companies owned the Linton, Duffey, and Tice ranches totaling more than 20,000 acres. In addition to their ranching enterprises, Baxter and Tooley were also interested in banking. In 1906 they joined with Dr. Henry B. Tice to organize the second bank in the Musselshell Valley, the Tooley, Baxter and Tice Banking House located in Twodot. In 1917 the Bank of Wheatland County opened in Harlowton with C.P. Tooley as president and E.C. Baxter as secretary and cashier.

Following the death of C.P. Tooley in October 1918, Baxter remained associated with Tooley's widow, Harriet Tooley, who continued her husband's insurance and other business activities. Baxter also invested in the oil industry, holding interests in Consumer's Oil Company of Harlowton and the Norwegian-American Oil Company.

Baxter, a Republican, was active in politics. He was elected to the state legislature in 1913 and served through 1917. During his legislative career he was active in the campaign to create Wheatland County, and his efforts met with success in 1917.

In 1890 Baxter married Frances Chapman and the couple raised five children, Robert, G.O. (Otis), Harry, Frances, and Helen. E.C. Baxter died in Harlowton on December 24, 1948.