At age 15, Madison broke the Pacific Coast 100-yard freestyle record with a time of 1:06.1 in a dual meet against the Multnomah Athletic Club.
On June 4, 1929, fifteen-year-old Helene Madison broke the Pacific Coast record in the women's 100-yard freestyle with a time of 1:06.1, competing at Crystal Natatorium in a dual meet between her home club and the Multnomah Athletic Club of Portland, Oregon. She also won the 100-yard backstroke event that same day.
This performance elevated Madison from a regional standout to a swimmer of recognized regional and coastal significance, as the Pacific Coast record encompassed competitors from a broader swath of West Coast swimming clubs. Breaking this record less than fifteen months after her Washington state record signaled a rapid trajectory of improvement under coach Ray Daughters' guidance.
Her emergence during this period coincided with an increasingly organized structure of amateur women's swimming competitions in the United States, governed by the Amateur Athletic Union (AAU). Success at the regional level was often a prerequisite for qualifying to compete at the national championships, which Madison would enter for the first time the following year, in 1930, with historic results.
This record marked another step in Madison's ascent toward becoming, within just a few years, the most dominant female freestyle swimmer in the world, ultimately holding nearly every official world freestyle record by the early 1930s.