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2016 Summer Mountain Trip Part 24; Colorado State 150 and Great Sand Dunes National Park & Preserve

Upon crossing the San Juan Mountains via Wolf Creek Pass I continued east towards Alamosa.  My next destination was at the north terminus of Colorado State Route 150 at Great Sand Dunes National Park & Reserve.


This article serves the 24th entry in the 2016 Summer Mountain Trip Series.  Part 23 regarding US Route 160 over Wolf Creek Pass can be found below.

2016 Summer Mountain Trip Part 23; US Route 160 over Wolf Creek Pass

The current CO 150 is a 16.114 mile north/south State Highway located entirely in Alamosa County which connects from US 160 to Great Sand Dunes National Park & Preserve.  The current iteration of CO 150 was created in 1974.  That said, CO 150 appears to be something of a State Highway designation that has refused to die.

The first CO 150 was added to the State Highway System in the late 1920s.  The first CO 150 began in Mosca and followed what is now Lane 6 east to current CO 150.  The original CO 150 followed the current highway to the vicinity of where the Great Sand Dunes Visitor Center is now located.  From the Great Sand Dunes CO 150 ascended eastward via what is now the Mosca Creek Trail to the 9,714 foot Mosca Pass in the Sangre de Cristo Mountains.  CO 150 upon cresting Mosca Pass entered Huerfano County and San Isabel National Forest.  From Mosca Pass CO 150 followed Huerfano County Roads 583, 581, 580, and 550 to CO 69 on the outskirts of Gardener.  The original CO 150 can be seen on a 1931 Clason Section Highway Map.


Referencing Mosca Pass it was a long established Native American Trail over the Sangre de Cristo Mountains by the time mining booms were beginning in Colorado.  Mosca Pass became a toll road which was maintained from 1871 through 1911.  This toll road appears to have been annexed by the State of Colorado for use as part of CO 150. 

At some point between 1939 and 1940 something appears to have had happened to CO 150 over Mosca Pass.  CO 150 appears as a normal State Highway on the 1939 State Farm Insurance Highway Map of Colorado but as a proposed highway on the 1940 edition.  Alamora.org refers to a flash flood which destroyed much of what was the Mosca Pass Toll Road but doesn't refer to when it happened on the Mosca Pass Trail Page



The 1947 Shell Highway Map of Colorado lists CO 150 over Mosca Pass as impassable.


CO 154 was deleted in 1954 likely due to the prospect of repairing Mosca Pass being deemed unfeasible.  CO 150 was reactivated in 1960 between Mosca and Great Sand Dunes National Monument.  CO 150 was deleted again in 1973 only to be brought back in 1974 under a heavy realignment which had it originate at US 160.

Regarding the Great Sand Dunes National Park & Preserve it encompasses an area of 149,028 acres.  The primary feature of Great Sand Dunes National Park & Preserve is the namesake Great Sand Dunes which are the tallest in the United States.  Great Sand Dunes National Monument was declared on March 17th of 1932.  The Great Sand Dunes would become a National Park on September 24th of 2004.


I should note that I visited the Great Sand Dunes in the Fall of 2015 in addition to the Summer of 2016.  My photos below are mix of the two albums from 2015 and 2016.

Below the Great Sand Dunes can be seen looking north from former CO 150 on Lane 6 in 2015.


Lane 6/Old CO 150 meets current CO 150 at the southern National Park Boundary.  Even from CO 150 the Great Sand Dunes are an obvious feature in the distance below the Sangre de Cristo Mountains.


The Great Sand Dunes feature sand drifts as high as 750 feet over an approximately 30 square mile area.  The Great Sand Dunes lie at the eastern corner of San Luis Valley.  San Luis Valley is encompassed by the San Juan Mountains to the west, bisected by the Rio Grande, and is closed in by the Sangre de Cristo Mountains to the east.  The bowl like shape of San Luis Valley caused it to fill into a giant lake (called Lake Alamosa) at some point in the past which left a great deal of sedimentation.  The sands left behind as Lake Alamosa dried largely blew east towards the Sangre de Cristo Mountains where they became trapped and began to accumulate into the Great Sand Dunes.  The Great Sand Dunes have also been continually fed by creeks running out of the Sangre de Cristo Mountains which leave deposits on the San Luis Valley floor.



From the Great Sand Dunes Visitor Center hikers can simply walk across Medano Creek to approach the dunes.





In 2015 I attempted to reach the 750 foot High Dune but ran out of time before sundown hit.  Hiking sand dunes is a slow process generally no matter what kind of footwear one uses I've found.




On my downhill descent former CO 150 over Mosca Pass can easily be observed looking east due to the obvious gorge of Mosca Creek. 


My summer return to the Great Sand Dunes in 2016 was far wetter than the previous year.  The difference in water volume in Medano Creek was substantial to say the least.





From the Great Sand Dunes I returned to US 160 south via CO 150.  I headed west on US 160 to Alamosa where I spent the night.  The next day would be a big one as it included visits to the Royal Gorge Bridge and Pikes Peak Highway. 

2016 Summer Mountain Trip Part 25; the Royal Gorge Bridge

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