Otis Reed "Dock" Marston (February 11, 1894 – August 30, 1979) was an American writer, historian and Grand Canyon river runner who participated in a large number of river-running firsts.

He spent the last thirty years of his life writing his magnum opus on the history of the first 100 Grand Canyon river runners.

William went to sea out of Boston in his teens where he became a master mariner and eventually owned a large shipping business sailing the Pacific out of San Francisco.

In later years, Mag became a prime mover in the University of California Alumni Association and Berkeley's Young People's Symphony Orchestra program.

[5] Marston began working as a financial planner for E. F. Hutton around 1930, and he soon realized he was better at his job if he understood the psychological make-up of his clients.

A friend of Marston's, Neill C. Wilson, participated in a San Juan River trip with Norman Nevills and thought it would be great to go with Norm on a Grand Canyon cruise.

[11] In 1944, Marston and his two daughters joined Nevills for a run from Mexican Hat, Utah, through Glen Canyon to Lee's Ferry.

Hudson had built the boat to design specifications provided by Canadian Naval Architect William Garden.

Other members in the Esmeralda II included Hudson's son Edward, Wilson "Willie" Taylor, and Bestor Robinson.

While the June Bug completed the cruise, not far below Separation Canyon, the gearshift on the motor of the Twin gave trouble, and the boat was taken in tow, much to the disgust of its crew.

[19][20] In June 1953, Dock and his wife Mag did a Grand Canyon river trip to do some reconnaissance for a possible Walt Disney film.

The river runners used small Sportyak II watercraft, and walked around a number of rapids they had never experienced at higher water flows.

While researching material for the manuscript (see below) about the 1889–90 Robert Brewster Stanton railroad survey, Dock realized an inscription made by fur trapper Denis Julien in 1836 had not been seen by river runners since the late 1800s.

[26] Not long after Dock and his friends located it, the reservoir waters rising behind Glen Canyon Dam submerged the inscription.

Marston would eventually amass an unparalleled collection of anything and everything to do with the history of the people who boated any part of the Colorado River watershed.

This extensive collection was eventually contained in 492 boxes, 60 albums, 163 reels of film, and 38 video cassettes and was the basis for Marston's manuscript on the first 100 river runners through the Grand Canyon.

The neighbor was Thaddeus Ames, a psychoanalyst at the top of his field, who had studied under Carl Jung and Sigmund Freud.

The death of his mother Idela in 1956, an amazing woman in her own right, the completion of Glen Canyon Dam in 1963, and the loss of his wife of forty-four years to cancer in 1968 were difficult blows.

Marston's manuscript was not published for more than 30 years afterward, finally going to press in 2014 as From Powell to Power: A Recounting of the First One Hundred River Runners Through the Grand Canyon.