As part of the Republican wave of the Senate in 1946, Ecton defeated Democratic former state Supreme Court Justice Leif Erickson by a vote of 54% to 46%.

[6] He served in the Senate for one term, having been narrowly defeated for reelection in 1952 by U.S. Representative Mike Mansfield, a Democratic college professor and Far Eastern expert.

[2] Ecton was the only Republican U.S. senator from Montana for over 75 years, between Joseph M. Dixon's failed re-election bid in 1913 and the 1988 election of Conrad Burns, who served from 1989 to 2007.

Currently, Ecton's papers are held by Archives and Special Collections at Montana State University.

The couple had two children, Eloise and Zales N. Jr.[1] Ecton resumed his ranching business until his death in Bozeman, Montana on March 3, 1961.