Does Iowa Have Natural Lakes or Islands?

No natural lakes exist in Iowa — the only U.S. state without any. But it has many artificial lakes and river islands.

Artificial Lakes (Reservoirs / Impoundments)

• Saylorville Lake (Des Moines River) — flood control, recreation.
• Red Rock Lake (Des Moines River) — largest in IA (15,000+ ac).
• Coralville Lake (Iowa River) — near Iowa City.
• Rathbun Lake (Chariton River) — southern IA.
• Lake Okoboji (Glacial) — exception: natural glacial lakes in NW IA (Iowa Great Lakes) — West Okoboji, East Okoboji, Spirit Lake. Formed 14,000 ya by Wisconsin glaciation.

Correction: Iowa Does Have Natural Lakes

The Iowa Great Lakes region (Dickinson County) contains natural glacial lakes — the only natural lakes in the state. West Okoboji (max depth 40 m) is a spring-fed, clear-water gem.

River Islands

• Mississippi River: Numerous — Pike Island, Sny Magill Island, Nine-Mile Island.
• Missouri River: Goat Island, Shepard Island.
• Des Moines River: Small alluvial islands.

Why the "No Natural Lakes" Myth?

Most of Iowa was tallgrass prairie + wetlands — drained for agriculture (99% lost). Glaciation left potholes, not lakes — except in the Des Moines Lobe (NW), where stagnant ice created the Iowa Great Lakes.

So: Natural lakes = YES (NW only). Islands = YES (riverine). Most "lakes" = reservoirs.