Embedded Files
 🚙 US-14A Mileage9.2                   GPS Coordinates  N 44.26.619  W 103.54.704    4,796 ft.
You're All Cracked Up Update2.pdfLesson Guide: PRINT
Both fascinating and uniqueÂ
A chasm straight and true
But how it formed and why right here Â
A mystery made for you
Field Exploration
Field Exploration
Eleven Hour Gulch – the hidden gem of Spearfish Canyon. Because of its slot-like form and steep, vertical walls, sunlight reaches its boulder-strewn depths for only a few moments each day. In this exciting exploration we'll take you into this rocky chasm and delve into the story of its formation as well as the geology behind its dramatic form and appearance.Â
This pdf Lesson Guide contains the specific directions for reaching our featured site as well as a detailed explanation of its geologic story. Mileage and coordinates are provided in each document and roadmaps and other learning aids can be found at the Lesson Resources link in the sidebar menu. The document is most useful if taken with you to the lesson site. Exercise extreme caution at the lesson site and along roadways.
Are you ready. . . . Let's Go!                        S. V. Fogarty  &  W. R. Stevens
*Mileage starts at the intersection Colorado Bvd. and US 14A near Spearfish.
Please review the safety advisories in the Lesson Guide and Use great caution should you decide to enter!
Eleven Hour Gulch
Eleven Hour Gulch
Eleven Hour Gulch access point. Parking is located just out of the photo in the lower left corner. EXERCISE EXTREME CAUTION when crossing roadway!
Eleven Hour Gulch access point. Parking is located just out of the photo in the lower left corner. EXERCISE EXTREME CAUTION when crossing roadway!
A chaotic assortment of boulders greet your entry into the gulch. EXERCISE EXTREME CAUTION if you decide to enter! Do not do so if you are not completely comfortable with hands and feet scrambling on slippery, unstable surfaces.
A chaotic assortment of boulders greet your entry into the gulch. EXERCISE EXTREME CAUTION if you decide to enter! Do not do so if you are not completely comfortable with hands and feet scrambling on slippery, unstable surfaces.
The Narrows
As one proceeds upstream through the gulch its vertical, igneous rock walls begin to narrow until eventually the chasm closes completely.
Continuation beyond this photographic point is not advised.Â
Eleven Hour Gulch (Fault?) viewed at 120ft. above road level. Note the linear trend of the gulch and its relatively smooth walls. Earthquake??
Eleven Hour Gulch (Fault?) viewed at 120ft. above road level. Note the linear trend of the gulch and its relatively smooth walls. Earthquake??
Looking back toward the highway along a smooth, vertical rock face.Â
Looking back toward the highway along a smooth, vertical rock face.Â
The gulch follows a narrow and linear course throughout in its entire lower reaches.
The gulch follows a narrow and linear course throughout in its entire lower reaches.
Gulch Map Annotated.pdfTopographic map showing Gulch drainage relationships and location.
Gulch Topographic Map. Print out for use at Lesson Site.
Gulch Topographic Map. Print out for use at Lesson Site.
Be sure to download our Onsite Geology Lesson PDF posted above for a detailed geologic investigation of this site.Â
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