This EarthCache is stand-alone due to its roadside access, but did you know that there are three EarthCache trails that follow along the often-floated sections of the Upper Missouri River? For more information and the first sites in each section, see the following links: (RM is ‘River Mile’)
Chouteau County Fairgrounds Campground and Canoe Launch (RM 0) to Coal Banks Landing (RM 41.5)
Coal Banks Landing (RM 41.5) to Judith Landing (RM 88.5)
>Judith River Landing (RM 88.5) to James Kipp Recreation Area (RM 149)
The Upper Missouri River Breaks National Monument plays host to a rich cultural history, including Lewis and Clark campsites, Native American heritage areas, old fur trade posts, steamboat landings, and homestead sites. For more information on planning a float down the river, please call the Missouri Breaks Interpretive Center (406-622-4000) or visit the BLM website.
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Viewpoint of the Missouri River Valley
View of the Upper Missouri River Valley from scenic overlook at mile marker 49? off highway 87 (photo by Ramia Bashara)
This EarthCache introduces you to the Upper Missouri River Valley. The Missouri river runs over 2,000 miles from its headwaters at Three Forks, Montana to where it meets with the Mississippi River in St. Louis, Missouri. It is the longest river in the United States. When taking into account its length with the Mississippi River included, it is the third longest river in the world. It is nicknamed ‘Big Muddy’ or ‘Muddy Mo’ due to the high content of silt carried in the water, making it look brown or muddy.
Muddy water from the Knife River flowing into the Missouri River at its confluence near Bismarck, ND (United States Geological Survey)
A valley is a depression in the landscape that is usually longer than it is wide. There are many different types of valleys, or at least names for them, depending on where you are in the country or the world. Two main types of valleys are referred to as ‘U-shaped’ and ‘V-shaped’. A U-shaped valley has been formed by the weight of a glacier and its scouring action while a V-shaped valley has been formed by the course of a river. These valleys are often not perfectly U or V shaped because of erosion such as weathering. A broad river valley, like that of the Missouri River at this location, indicates an older age as it has had time to flood and ‘flatten’ the landscape. A narrow river valley, like that of the Missouri River 50 miles east of here, indicates a younger age as the river’s erosive power is much stronger and creates a steep-walled canyon. Broad river valleys are characterized by floodplains. Floodplains are a result of a river regularly flooding, overflowing, and depositing sediment at the site of the overflow. Generally floodplains are formed where a river is meandering. A meandering river is a classification for the pattern in which a river flows across the land. Other classifications are braided or straight rivers. Furthermore, a floodplain is a depositional landform feature. A depositional landform feature is one where eroded material is deposited, just as the name indicates. There are also erosional landform features, such as the steep-walled canyon of a river-shaped valley, further downriver. An erosional landform, as you may have already guessed, is one where the landscape has been eroded away to form new characteristics. The erosional or depositional features in a landscape are also dependent on the river gradient. The river gradient is the angle at which the water flows downriver. A high gradient reveals a steep angle and swift flow of water, where a low gradient reveals a slower moving and a more nearly level river. Depositional landforms are a fluvial process. The term fluvial is associated with rivers and streams and the deposits and landforms that are constructed by them. Additionally, floodplains are an alluvial feature. An alluvial feature is an area where fluvial deposition is concentrated, like at the mouth of a canyon, where an alluvial fan will form.
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To claim this cache: Answer the following questions and send the answers using Geocache's messaging tool.
Q. Looking into the valley from the viewpoint you are standing on, how is the river flowing? Is it meandering, braided, or straight? Do you see a floodplain?
Q. What area of the river mentioned in this EarthCache would you find a high stream gradient? A low stream gradient? (Hint: this can be deduced by reviewing the definitions of broad and narrow river valleys.)