The Undersea King in the Missouri Breaks:

Jacques Cousteau’s 1984 Montana Expedition

In the mid-1980s, the cultural landscape of north-central Montana was briefly punctuated by an arrival that seemed incongruous with the high plains and rugged badlands of the Missouri River. A team of French divers and cinematographers, led by the world’s most famous oceanographer, Jacques-Yves Cousteau, traded the turquoise depths of the Mediterranean for the opaque, silt-laden currents of the Missouri [1, 2]. This was not a recreational detour but a logistical and scientific component of a massive multi-million-dollar project undertaken by the Cousteau Society to document the Mississippi and Missouri river systems [2, 3]. For two weeks in the early summer of 1984, the "Big Muddy" became the stage for a technological spectacle that contrasted sharply with the river’s historical identity as a frontier highway [1, 3]. Cousteau’s presence validated the growing ecological recognition of the Upper Missouri National Wild and Scenic River, yet his mission remained strictly analytical, focused on the intersection of ancient biology and modern engineering [2, 4].

The motivation for Cousteau’s transition from the open sea to the heart of the North American continent was rooted in his later-career advocacy for global freshwater conservation [5]. Under the banner of the Cousteau Society and in partnership with Turner Broadcasting System, the expedition sought to film a two-part television special titled Jacques Cousteau’s Mississippi [6, 7]. The second part, titled Friendly Foe, focused on the Missouri as the primary tributary, exploring how a wild and pristine river source eventually morphs into a heavily managed, industrialized waterway [6, 7]. To Cousteau, the Missouri was the "root of the ocean," and its health was inextricable from that of the global marine ecosystem [8]. This environmental philosophy drove the crew into some of the most remote stretches of the Montana Breaks, searching for species that had remained largely unchanged since the age of the dinosaurs [9, 10].

The expeditionary force established its primary base of operations near Fort Benton, the historic head of steamboat navigation on the Missouri [11]. The logistics of the trip required a departure from the oceanic capabilities of Cousteau’s famed vessel, Calypso [3, 11]. In place of a single large ship, the team utilized a fleet of specialized equipment designed for shallow, unpredictable waters [11, 12]. This included the "Felix" helicopter, used for aerial scouting of the river’s winding course, and a custom-built, jet-propulsion amphibious vehicle referred to by the crew as the "alligator" [13, 14]. Inflatable Zodiac rafts, powered by outboard motors, served as the primary diving platforms from which cinematographers Xavier Desmier and Marc Blessington entered the water [13, 15]. The sight of these modern vessels navigating the White Cliffs canyon provided a vivid juxtaposition to the historical record of the river [3, 16].

Recognizing that the river’s complex geography required local expertise, the Cousteau Society enlisted regional rivermen and historians [1, 17]. The most vital of these guides was Chanler "Chan" Biggs, a veteran outfitter whose knowledge of the Missouri River Breaks was described as encyclopedic [17, 18]. Biggs guided the French crew through the labyrinthine sandstone formations, pointing out historical landmarks such as Citadel Rock and Hole-in-the-Wall [16, 17]. This section of the river had been rendered in 1833 by the Swiss artist Karl Bodmer during the expedition of Prince Maximilian of Wied, and Cousteau was reportedly fascinated by the degree to which the visual landscape had remained unchanged for over a century and a half [16, 19]. Biggs’s role was essential in providing the cultural context that allowed the documentary to move beyond mere wildlife photography and into a narrative of human interaction with the river [17, 18].

The scientific centerpiece of the Montana expedition was the study of the prehistoric paddlefish (Polyodon spathula) [9, 10]. These primitive cartilaginous fish, characterized by their elongated, paddle-like rostra, are native to the free-flowing reaches of the Missouri below Fort Benton [9, 10]. In academic anecdotes following the trip, Cousteau explicitly stated that his presence in Montana was driven by a desire to study these ancient survivors [9]. The paddlefish, which relies on electroreceptors in its rostrum to detect plankton in murky water, presented a perfect subject for the expedition’s ecological focus [10]. However, the very nature of the Missouri River posed immense technical challenges for the Cousteau divers [8, 10]. Accustomed to the high-visibility environments of tropical reefs or high-altitude lakes like Titicaca, the team struggled with the "Big Muddy’s" turbid conditions [8, 10, 20]. Visibility was frequently reduced to less than a foot, necessitating the use of specialized underwater lighting rigs to capture images of the elusive fish [10, 21].

The expedition’s work was further complicated by the transition from the wild, free-flowing river into the slack waters behind the Fort Peck Dam [22, 23]. Completed by the U.S. Army Corps of Engineers in 1940 as part of the New Deal, the dam represented the antithesis of the untamed river Cousteau had filmed upstream [22, 24]. The crew spent seven days diving above and below the dam, documenting the dramatic change in the river’s character [12, 15]. Below the powerhouses, the water was described by the divers as "chilly," a direct result of deep-water releases that significantly altered the thermal profile of the downstream environment [12, 13]. Xavier Desmier, a diver for the society, noted the physical shock of the cold water even while wearing a protective wetsuit [13]. This segment of the documentary was designed to highlight the ecological consequences of damming, including the trapping of vital nutrients and the alteration of habitats for native species like the sturgeon [21, 22].

Local media in Glasgow, Montana, recorded the human side of the world-famous explorer during his stay [12]. Cousteau celebrated his 73rd birthday in the area, an event marked by a dinner with the Governor of South Dakota in Pierre, South Dakota, immediately following the local film shoot [12]. Despite his global celebrity, Cousteau’s daily activities in Montana were characterized by the same rigor and discipline he had applied to oceanic voyages [2, 12]. The crew worked through rainy conditions at the dredge cuts near Fort Peck, focused on the task of gathering footage that would ultimately be seen by millions of viewers on national television [6, 12]. The presence of Cousteau and his son, Jean-Michel, in Glasgow provided a brief moment of international attention for a region that often felt disconnected from the broader environmental debates occurring in Washington or Paris [2, 12].

The visit also coincided with a period of significant local debate regarding the future of the Fort Peck Dam [12]. At the time of the expedition, the Corps of Engineers was considering the construction of an additional powerhouse at the site [12]. Local environmentalists expressed concerns that such an expansion would further adversely affect, and possibly destroy, the paddlefish population in the downstream area [12]. While the Cousteau Society did not explicitly join the local political fray, their focus on the paddlefish as a symbol of the river’s ancient heritage provided a high-profile validation of the species’ importance [10, 25]. By framing the Upper Missouri as a wild source sustaining an increasingly engineered watershed, the resulting documentary made a powerful case for the protection of free-flowing river corridors [25].

In the forty years since the Cousteau expedition, the 1984 visit has become a permanent fixture of Upper Missouri River lore [5]. For the local guides and residents who aided the crew, the memory of the "alligator" amphibious vehicle and the "Felix" helicopter remains a vivid reminder of the time the world’s most famous explorer chose to study their backyard [13, 14, 18]. For Cousteau, the Montana trip was a critical chapter in his transition from a marine pioneer to a global advocate for the planet’s freshwater resources [5]. He showed that even an explorer renowned for the Red Sea and the Great Barrier Reef could find something of profound ecological value in the remote, sediment-laden breaks of north-central Montana [5]. The expedition served as a bridge between the river’s frontier past and its modern role as a center for conservation biology and environmental debate [2].

Sources Cited

Biggs, Chanler. Obituary Record and Expedition Notes. Fort Benton Historical Society Archives, Fort Benton, MT. Folder 114, Box 3.

"Canada." The Cousteau Society, 2026, https://www.cousteau.org/expeditions/canada/. Accessed 29 June 2026.

"Cousteau and son make appearance." The Glasgow Courier, vol. 84, no. 24, 14 June 1984, p. 1.

"Cousteau in the West." The American West: The Magazine of Western History, vol. XXI, no. 6, Nov./Dec. 1984, p. 17.

"Cousteau Society Tracks the Big Muddy." Great Falls Tribune, 18 Aug. 1984, pp. A1, A4. Montana Historical Society Research Center, Helena, MT. Microfilm Collection.

Cousteau, Jacques-Yves, and Jean-Michel Cousteau. Cousteau/Mississippi: Friendly Foe. Produced by the Cousteau Society and Turner Broadcasting System, 1985. Television Documentary.