Mountain Interval is a 1916 poetry collection written by American writer Robert Frost. It is Frost's third poetic volume and was published by Henry Holt. It was republished in 1920. Frost made several alterations in the sequencing of the collection and released a new edition in 1921. Five lyrics of the earlier collection were compiled next under the title "His Wife". In this volume only three poems are written in dramatic monologue. Summary by Wikipedia