1950 Dickinson Dam on Heart River At Dickinson, ND

(Satellite)

It had a structural height of 65' [20m]. [Google search results]

It impounds the Edward Arthur Patterson Lake.

Bureau of Reclamation posted three photos with the comment:

The Dickinson Dam on the Heart River near Dickinson, ND, was built in just one year (1949-1950) and stands 2,275 feet [693m] long and 24 feet [7.3m] wide. Over the years, upgrades have boosted its water capacity and made it a prime spot for recreation! 

With 1,191 acres of water, 1,276 acres of land, and 22 miles of shoreline, there's something for everyone – from fishing and boating to hiking and disc golf. Come enjoy the outdoors at this hidden gem

1

2

3

I had to go back to Dec 2010 to find water going over the spillway.

Google Earth, Dec 2010

It is not just the TVA valley (2025 TVA Flood) that is wet this year.

noaa

It is just 1.5' (a half meter) from going over the service crest.

noaa

I presume that this is the auxiliary spillway. It looks like unprotected earth. At least it is undisturbed earth. I guess that is a lot stronger than the earth used to build the dam.

Satellite

Osborn's Studio, “Adler Construction Company (Dickinson Dam Construction),” Southwestern North Dakota Digital Archive At the Dickinson Museum Center, accessed February 27, 2025, https://dmc.omeka.net/items/show/38259.

In 1954, just four years after it was built, a flood tore the spillway apart.

“Dickinson Dam Flood,” Southwestern North Dakota Digital Archive At the Dickinson Museum Center, accessed February 27, 2025, https://dmc.omeka.net/items/show/26578.

Citation: Osborn, “Dickinson dam flood,” Southwestern North Dakota Digital Archive At the Dickinson Museum Center, accessed February 27, 2025, https://dmc.omeka.net/items/show/5100.

At least there was competent bedrock under the spillway so that the crest was not undercut.

Dickinson Dam Flood,” Southwestern North Dakota Digital Archive At the Dickinson Museum Center, accessed February 27, 2025, https://dmc.omeka.net/items/show/26572.

Osborn, “Dickinson dam flood,” Southwestern North Dakota Digital Archive At the Dickinson Museum Center, accessed February 27, 2025, https://dmc.omeka.net/items/show/5070.