San Diego-Arizona Railroad, The Impossible Railroad

At the turn of the 20th century, during the great era of railways, each city on the western seaboard of the North American continent needed a fast and reliable supply line from the east to ensure growth and prosperity. San Diego was a small port city at that time and business pioneers decided that for the city to grow, it they needed a direct link connecting with El Centro to the east, to supplement the supply line from its larger, northern neighbor, Los Angeles. The San Diego and Arizona Railroad was proposed.

The builders soon realized that the rail link to El Centro presented massive engineering challenges. Conditions were harsh and the treacherous mountain ranges were near impassable with gigantic boulders, deep valleys and numerous ridges and canyons. The prospects were so hopelessly against them, that it became known as "the Impossible Railroad", a name made more apt by the hostile desert climate, with temperatures in the summer soaring to over 110 degrees Fahrenheit.



It took the construction of 17 tunnels, ranging in length from 290 feet to half a mile, and 20 trestles to complete the most mountainous eleven-mile stretch, but the railroad was finally completed in 1919.

Maintaining the Carrizo Gorge section with its numerous tunnels and trestles was a constant challenge, especially in this earthquake-prone country. When an earthquake collapsed one of the tunnels in 1932, the engineers chose an alternate route around the ridge. But the alternate route necessitated the construction of a bridge over a steep lateral gorge known as the Goat Canyon. The wooden trestle that was constructed here, remains to this day, the longest, tallest curved wooden trestle ever built in the United States. Over 600ft long and 180ft high in the center, the magnificent structure is an engineering marvel that very few has seen.

The last passenger train to travel the full length of the railroad left San Diego on Jan.11, 1951, but the railroad continued to ferry freight through the Carrizo Gorge until September 1976 when tropical storm Kathleen washed out the impossible railroad in numerous places. The damage to the section through Carrizo Gorge was so massive that it remains closed to this day. The abandoned railroad now attracts adventurist and railway buffs who try to follow the rails all the way from the high point in Jacumba down the gradient to Ocotillo in a spectacular journey of about 22 miles through a stark desert landscape, dotted with the efforts of railroad engineers to tame this wilderness, an effort that came to nought.


































A scale model of the Goat Canyon trestle at San Diego Model Railroad Museum.


A model of the Goat Canyon trestle at San Diego Model Railroad Museum.








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Top 40 Detailed Close Ups of Arthropods

An arthropod is an invertebrate animal having an exoskeleton (external skeleton), a segmented body, and jointed appendages. Arthropods include all insects, arachnids, and crustaceans. Their body plan consists of repeated segments, each with a pair of appendages. Their versatility has enabled them to become one of the most species-rich members on the planet.

They have over a million described species, making up more than 80% of all described living animal species. They range in size from microscopic plankton up to forms a few meters long.

The USGS Native Bee Inventory and Monitoring Program designs and develops large and small-scale surveys and identification tools for native bees. A vital aspect of the program is to create accurate and detailed pictures of native bees as well as the plants and insects they interact with.

On their 1200+ Flickr photostream, the USGS Bee Inventory and Monitoring Lab (USGS BIML) has uploaded an astounding collection of macro photographs that you can see in full resolution. The detail and clarify is unlike anything I’ve ever seen.

Hidden Unseen went through all 1200 photos earlier today and compiled our 40 favourites. Be sure to check them out on Flickr to appreciate the volume of work they have shared for the benefit of all visitors.



1. Unknown Wasp




2. Yellow Jacket Mimic Fly




3. Female Northern Black Widow Spider
(Latrodectus variolus)





4. The Endangered Karner Blue
(Lycaeides melissa samuelis)




5. Melissodes dentiventris




6. Beetle on glass




7. Black Horse Fly
(Tabanus atratus)





8. Augochlora regina



9. Oblong-winged katydid
(Amblycorypha oblongifolia)





10. Megachile-campanulae




11. Lasioglossum nr longifrons




12. Lace Bug




13. Rove Beetle




14. Trypoxylon mexicanum




15. Centris haemorrhoidalis



16. Cone Head




17. Agapostemon coloradinus




18. Leptochilus acolhuus




19. Harlequin Bug Eggs
(Murgantia histrionica)




20. Polistes metricus




21. Spider Wasp




22. Gryllus species




23. Hoplitis truncata




24. Deer Fly
(Tabanidae)





25. Drepanaporus collaris




26. Triepeolus donatus




27. Drepanaporus collaris




28. Sharpshooter
(Oncometopia orbona)





29. Trypoxylon mexicanum




30. Yellow Jacket Mimic Fly




31. Pearl Crescent
(Phyciodes tharos)





32. Camel Cricket
(Diestrammena asynamora)




33. Harlequin Bug Nymphs
(Murgantia histrionica)





34. Lachnopus guerinii




35. Bombus griseocollis




36. Coelioxys sayi




37. Unknown Spider




38. Brown marmorated stinkbug
(Halyomorpha halys)




39. Osmia sandersoneae




40. Dianthidium curvatum





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