Lakes

The Reservoirs

Six impoundments across the Great Plains — and the stories buried beneath them.

Below the surface of every Great Plains reservoir lies a river valley that people called home — and the dams that flooded those valleys were not acts of nature.

Why this stretch

The river here.

The six Missouri River reservoirs — Fort Peck Lake, Lake Sakakawea, Lake Oahe, Lake Sharpe, Lake Francis Case, and Lewis & Clark Lake — are the defining fact of the Missouri River in the twentieth century. The Pick-Sloan Plan, authorized by Congress in 1944, authorized their construction. The Army Corps of Engineers built the dams. And the communities, farms, and ceremonial sites that lay in the inundation zones were flooded. The Mandan, Hidatsa, and Arikara Nation (MHA Nation) lost more than 150,000 acres of bottomland to Garrison Dam and Lake Sakakawea — the most productive agricultural land the Three Affiliated Tribes possessed. The Standing Rock Sioux, Cheyenne River Sioux, Crow Creek Sioux, Lower Brule Sioux, and Yankton Sioux collectively lost hundreds of thousands of additional acres to Oahe, Big Bend, Fort Randall, and Gavins Point dams. Entire towns relocated. Cemeteries were moved or flooded. The historic confluence of the Knife River with the Missouri — site of Mitutanka and Ruptáre, the Mandan villages where Lewis and Clark spent their first winter — now lies beneath Lake Sakakawea.

The two paddleable reaches in this chapter are tailwaters: the 75-mile Garrison tailwater through central North Dakota to Bismarck, and the 84-mile Oahe tailwater from Pierre through Lake Sharpe to Big Bend Dam. Both are dam-controlled, which means consistent flows and cold water year-round. Both offer genuine paddling value — Cross Ranch State Park's free-roaming bison herd is visible from the Garrison reach; the Big Bend horseshoe on the Oahe/Sharpe stretch is one of the most dramatic river formations in the entire Missouri basin. But paddling them honestly means holding both realities at once: the recreation and the history that made it possible.

At a glance

Quick facts.

159 (tailwaters)
River miles
Easy to Moderate
Difficulty
June – September
Best season
None required
Permits
The reaches

Paddle segments.

75 mi Easy June - September

Garrison Tailwater to Bismarck

75 miles of free-flowing Missouri River below Garrison Dam through central North Dakota to Bismarck.

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84 mi Moderate June - September

Oahe Dam Tailwater to Big Bend

Approximately 50 miles of Missouri River below Oahe Dam near Pierre, SD, through Lake Sharpe to Big Bend Dam.

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Know before you go

Drowned homelands & reservoir wind safety

The Garrison and Oahe tailwaters are dam-controlled and relatively consistent, but they feed into and draw from reservoirs that behave like lakes, not rivers. Wind is the governing safety concern. Lake Sakakawea covers 307,000 acres; Lake Oahe covers 374,000 acres. On either reservoir, afternoon winds can build 2- to 3-foot waves within an hour, pinning paddlers on shore for 12 to 36 hours. The standard practice on both lakes is to launch at or before first light, cover distance in the calm morning window, and make camp well before noon if the forecast shows any wind. Being wind-bound is not a sign of bad planning — it is expected. Factor at least one weather day per five days of travel on any reservoir crossing.

The water is cold year-round from dam releases. Immersion on the Garrison tailwater (water released from the bottom of Garrison Dam) can incapacitate in minutes even in August. Wear or have immediate access to your PFD at all times. On the Oahe/Sharpe section, the reservoir's minimal current means sustained paddling effort is required — 14 to 21 miles per day is realistic at a leisurely pace, slower in headwinds. Both reaches are exceptional for walleye and northern pike fishing, and both pass through country of deep historical weight: the Knife River Indian Villages, Double Ditch Indian Village, and the Lower Brule Sioux Reservation speak to the peoples who lived on this river long before the dams.

Highlights

What to look for.

Map preview

See the corridor.

The Reservoirs river corridor map
Plan your trip

Logistics.

The Garrison tailwater puts in at the Garrison Dam Tailrace (47.5025°N, 101.4326°W), accessible off ND-200 west of Washburn. Take-out at Fort Abraham Lincoln State Park or Bismarck's Sanger Boat Ramp. The Oahe tailwater starts at Farm Island Recreation Area below Oahe Dam near Pierre, SD (44.37°N, 100.35°W), and ends at Big Bend Dam near Fort Thompson. Both reaches have multiple mid-reach access points for shorter day or overnight floats. Check daily dam discharge schedules (USACE Missouri River Water Management, nwd-mr.usace.army.mil) before launching — release fluctuations can raise or drop the river a foot or more within hours.

Access points
Access pointMile
Garrison Dam TailraceRM 1390
StantonRM 1370
WashburnRM 1355
Cross Ranch State ParkRM 1340
Bismarck / Sanger Boat RampRM 1320
Fort Abraham LincolnRM 1315
Oahe Dam / Farm IslandRM 1072
Pierre City RampRM 1065
DeGreyRM 1040
Big Bend Dam / Fort ThompsonRM 987
Hazards & considerations
  • Cold water from dam releases even in summer
  • Dam release fluctuations - check daily schedule
  • Wind exposure
  • Occasional powerboat traffic near Bismarck
  • Wing dams and rock structures near Bismarck
  • Wind exposure on wide reservoir - can create large waves
  • Being wind-bound for multiple days is possible
  • Minimal current in reservoir sections requires sustained paddling
  • Cold water from dam releases
  • Limited access points along Lake Sharpe
  • Barge and boat traffic