Eastern Mojave Vegetation U. S. Highway 91  
 

Tom Schweich  

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Literature Cited
  For the most part US Highway 91 has been replaced by US Interstate 15. There are two segments of US Highway remaining. A northern segment follows a route abandoned by I-15 from just south of Pocatello, Idaho, through Logan, Utah, and then into the Great Salt Lake basin, where I-15 is rejoined. The southern segment of US Highway 91 heads west from Saint George, Utah then turns south to Littlefield, Arizona, bypassing the route that I-15 now takes through the Virgin River Canyon.
   
Northern segment of US Highway 91 is below.

Other Articles: Interstate 15: Idaho Exit 36  

Junction: US Interstate 15, north to Pocatello, Idaho, or south to Salt Lake City, Utah.

The reason to take US Hwy 91 south rather than I-15 would be to view the spillway of Pleistocene Lake Bonneville into the Snake River drainage at Zenda and Red Rock Pass.

Literature Cited:
- Hart, William S., Jay Quade, David B. Madsen, Darrell S. Kaufman, and Charles G. Oviatt., 2004.  

Locations: Zenda.  

Zenda

Location in southern Idaho, off US Highway 91.

Zenda is given as the location of an alluvial dam that held the highest stand of Pleistocene Lake Bonneville for 500 to 1000 years before it eroded, creating the Bonneville Flood.

Literature Cited:
- Hart, William S., Jay Quade, David B. Madsen, Darrell S. Kaufman, and Charles G. Oviatt., 2004.  

Locations: Red Rock Pass.  

Red Rock Pass

Bedrock threshold for the Provo shoreline of Pleistocene Lake Bonneville.
    Idaho Above.
Utah below.
 

Locations: Logan.  

Logan

 

Other Articles: Interstate 15: Utah Exit 364  

Brigham City

Junction: US Interstate 15, south to Salt Lake City, Utah, or north to Pocatello, Idaho.
    Northern segment of US Hwy 91 above
Southern segment of US Highway 91 below.

Other Articles: Interstate 15: Saint George

Locations: Saint George.  

St. George

  • Junction:
    • US Interstate 15, North to Salt Lake City, South to Las Vegas.
  •    

    Santa Clara

     

    Literature Cited:
    - Retallack, Gregory J., 2009.  

    Locations: Ivins.  

    The town of Ivins is just to the northeast of the highway.

    Just to the northeast of Ivins is a paleosol collection site in the Triassic to Jurassic Chinle, Moenave, and Kayenta formations used by Retallack in his 2009 study of greenhouse crises of the past 300 million years. Retallack used stomatal index data for fossil Ginko and related leaves as a proxy for past CO2 spikes and paleosol chemical data as proxies for temperature and humidity changes. These data show that global warming due to CO2 rise is a not a unique event in earth history and that the magnitude of the coming anthropogenic greenhouse pales in comparison with past greenhouse spikes at times of global mass extinctions.

       

    Shivwits

     

    Other Articles: Gunlock Road: at Old US Hwy 91  

    Junction: County Route 3184 "Gunlock Road"

    Other Articles: Mojave Desert Joshua Tree Road: at US Hwy 91  

    Junction:

    Junction: Mojave Desert Joshua Tree Road to area where Frasera albomarginata was found.

    Other Articles: Beaver Dam Mountain Road: at old US Hwy 91  

    Junction: Beaver Dam Mountain Road
       

    Utah Hill Summit

     
       

    CastleCliff

     

    Other Articles: Mojave Desert Joshua Tree Road: at US Hwy 91  

    Junction:

    Junction: Mojave Desert Joshua Tree Road
        Utah above
    Arizona below

    Other Articles: Interstate 15: Littlefield  

    Littlefield

    Junction:
    • US Interstate 15, north to St. George; south to Las Vegas.
       

    Literature Cited

      A list of all literature cited by this web site can be found in the Bibliography.
     
    Hart, William S., Jay Quade, David B. Madsen, Darrell S. Kaufman, and Charles G. Oviatt. 2004. The 87Sr/86Sr ratios of lacustrine carbonates and lake-level history of the Bonneville paleolake system. GSA Bulletin. 116(9/10):1107-1119.

    Location records referred to by this literature:

     
    Retallack, Gregory J. 2009. Greenhouse crises of the past 300 million years. GSA Bulletin. 121(9/10):1441-1455. {TAS-pdf}

    Location records referred to by this literature:

    If you have a question or a comment you may write to me at: tas4@schweich.com I sometimes post interesting questions in my FAQ, but I never disclose your full name or address.  


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    Date and time this article was prepared: 4/6/2014 9:14:28 AM