EARTHCACHE DESCRIPTION
This earthcache takes you to Hell’s Gate, a very constricted, abrupt narrowing of the Fraser River, a few kilometres south of Boston Bar, British Columbia. The towering rock walls of the Fraser River Canyon plunge toward each other forcing the waters through a passage only 35 metres (115 ft) wide. The Fraser Canyon in general, and Hell’s Gate in particular are the narrowest parts of the 1,375 kilometres-long (854 miles) Fraser River, from its headwaters in the Rocky Mountains near Mt. Robson to its discharge into the Strait of Georgia. From the Rockies, it flows in a northwesterly direction until a bit north of Prince George, where turns westward and then southward. From Prince George, it flows almost straight south to Hope where it makes its last major turn and flows in a south-west direction to the Strait, south of Vancouver.
The Fraser is the longest river and also has the largest basin of any river that’s wholly within the boundaries of British Columbia; it’s also the eleventh longest river in Canada. The Fraser basin covers 233,000 square kilometres (89,960 sq miles). Besides this, the Fraser is the longest undammed river on North America’s west coast.
By the time the Fraser’s waters reach Hell’s Gate, most of its major tributaries, including the Thompson, Chilcotin, and Nechako, have flowed into the river. The remaining major tributaries are west of Hope and include the Chilliwack, Harrison, and Pitt. To get a feel for the quantity of water flowing through Hell’s Gate, include on your trip, a stop downstream of Hope, after the river has widened out and you will see much more surface area.
This earthcache looks at the area’s geology and history, and also looks at how we humans can and do alter our environment for better or for worse.
The background photos were taken from the bridge, looking north and are of the approximate same part of the river. Right is the highest the water reached in 2019, and left is from September 2018. Note, the water level and turbulence differences at the beginning and end of the season. Note also the fishways and the very hard rock to which they were attached. Unlike in the September photo, this river is always brownish; the September photo was taken at a favourable time of day for nice water reflection.
PLANNING YOUR TRIP
The earthcache is at the centre of the river, close to the popular Hell’s Gate tourist attraction, on Highway 1, an East-West highway. Because the Fraser Canyon lies close to true north to south, Hwy 1 West travels south in the Canyon. For convenience, my notes use the compass directions north and south.
You can reach GZ either on foot or via the Airtram. To walk down into the Canyon: Begin at Waypoint 1, and walk down a rough, gravel, service road. A sign at the top once told the reader that the river is “600 feet below this point.” Once you reach the river, you may walk or ride the Airtram back up to the highway. If you return via the Airtram, buy your ticket in the gift shop and walk on a safe trail beside the highway to reach your car; there’s no charge to walk the service road, but the Airtram has a charge. The cache’s terrain rating is a 1.5 for those who take the Airtram (Although the area is accessible, the bridge could be a challenge for wheelchairs). However, the rating would be a 5 for those who walk the service road which is 1.6 kilometres long with a 183 metre elevation change, and is hot in the summer. That said, the service road is through an area of pine trees and has some shade.
The only assessable parking is on the highway’s southbound side, but there’re no left turns to it. To reach the Airtram parking from Yale, drive past the Airtram for about 1.4 km, to the turnaround at Waypoint 4. This turnaround is an unmarked pullout beside the road. There’s also no left turn from this parking lot back onto the highway. If you want to drive north to Boston Bar, turn right and use Waypoint 1 to turn around.
Within the attraction’s visitor centre are excellent educational displays telling the visitor about the area’s early European influence, the building of the railroads, the life cycle of the salmon, and the need for the nearby fish ladders to help the salmon in its biological drive to return home. The displays have no entry fee. On the outdoor deck there’s also a schematic diagram of the river channel through Hell’s Gate; it’s worth a stop.
The Hell’s Gate Airtram and visitors’ area are seasonal, open from about mid-April to early October; check their website for hours (and rates if you plan to use the Airtram). If you’re able to plan your visit, the following gives you an idea of what you’ll see: At the beginning of the season (April to about June), the water in the river becomes progressively higher and you’ll see (and hear) its raging torrent, but little or nothing of the fish ladders. As the season progresses, more and more of the fish ladders become visible until, at the end of the season (September), they’re quite visible. Throughout the summer, from some time in July, you’ll see the salmon in the river, especially near the banks as they enter the fish ladders.
If you drive along the highway in the off-season, stop and look down into the canyon. Not only are the visitor centre and Airtram closed, but the service road is also gated and locked at the bottom. However, a sign on the wall of the upper Airtram station is worth reading. During the off-season, if you stop at the upper Airtram station or at some other place near Hell’s Gate, you may log a “Write Note” but any “Found It” logs will be deleted.
A LITTLE GEOLOGY
Although experts (depending on their viewpoint) vary on exactly how much of the river they call the Canyon; in simplest terms, one can think of it as being that portion of the Fraser from Lytton downstream to Yale.
Geomorphological evidence indicates that the Fraser’s course was reversed to flow southward during the Miocene period (23.7–5.3 million years ago) when the river cut into the uplifting Interior Plateau, to form the Canyon. Part of the river’s course follows north-south fault lines, and in the Canyon area, it’s squeezed between the Cascade and the Coast Mountain Ranges. Andrews states that, “Although the exact causes of drainage reversal remain unresolved, the reversal likely followed stream capture in response to enhanced glaciofluvial erosion and uplift of the Coast Mountains.”
The Canyon portion of the river flows through old lava flows of the southern Chilcotin Group, dating to the Pliocene Period (5.3 to 2.6 million years ago), but the origins of the volcanic vents have yet to be discovered. As you drive, take note of the old exposed volcanic cliffs of these lava flows. Also take note of how hard the rock is and consider the difficulties of building transportation routes through the area. If your trip takes you to Cache Creek, think about the differences between the hard rock of the Fraser Canyon cliffs and of the landslide-prone sedimentary structure of the Thompson River Canyon (east and north of Lytton).
About 10 kilometres south of Hell’s Gate is Alexandra Bridge Provincial Park. Within the park, an easily-walked trail goes down into the Canyon to an historic suspension bridge over the river. This is another very good place to observe the river and its canyon from close-up. As an added bonus, near the bridge are two traditional caches and the bridge is a virtual cache. Finally, in considering the area’s geology, those interested in more in-depth information may want to check the references below; they also include some good illustrations and maps.
A LITTLE HISTORY AND A CROWDED CORRIDOR
For millennia, the First Nations People lived in what came to be known as the Fraser Canyon. They had fishing camps and learned to navigate the river. They had even learned to negotiate the Hell’s Gate via a system of rope ladders, to move upstream or downstream. During Simon Fraser’s epic overland journey from east of the Rocky Mountains, to the Strait of Georgia (1806-08), he said this about this area: “I have never seen anything equal to this country. . . We had to pass where no human being should venture. . . Yet in those places, a regular footpath impressed, or rather indented, by frequent travelling upon the very rocks. And besides this, steps were formed like a ladder . . . suspended from the top of precipices . . . furnished a safe and convenient passage to the Natives.” Indeed, it was Fraser who first called this constriction in the river, “the gates of Hell.”
After Fraser’s visit to the area, the Fraser Canyon remained as it had been, until 1858, when gold was discovered in the Cariboo, on a Fraser River tributary. Thus began the Fraser Canyon’s importance as a transportation corridor, and the first road was built to access the Cariboo Gold Rush. Later, the Canadian Pacific Railroad was built in the 1880s, followed by the Canadian National Railroad in the 1910s. These are still Canada’s most direct rail lines from the east, to the Port of Vancouver on the edge of the Pacific Ocean. The Cariboo Road was gradually upgraded but the Fraser Canyon section wasn’t completed until the late 1960s. This portion included some of the most difficult and expensive highway work in Canada (Look at the great rock walls as you drive and you’ll see why). Thus, today three major transportation arteries squeeze their way through the Fraser Canyon and the very narrow Hell’s Gate area. If you’re well-travelled, do you know of any other transportation corridor that’s so crowded and that also had so much heavy rock-work?
During your visit, observe the numbers of cars and trucks on the highway, as well as the frequency of very long trains on the two rail lines. Observe also, the number of tunnels needed by the highway and the rail lines to squeeze through the canyon and past Hell’s Gate.
CHANGES TO THE ENVIRONMENT
People have made changes to their surroundings from the beginning of time: sometimes for the better, sometimes for the worse. Some changes are intentional and some accidental. People also made two major changes to the river channel at Hell’s Gate. The change for the worse was accidental and occurred in 1913-14 during the building of the CN Railroad, when blasting caused rock to tumble into the river. One large slide even took out 50 feet of the new railway, further constricting an already-tight squeeze for the passing waters. One Visitor Centre’s sign states that millions of fish died, some runs to spawning grounds became extinct, and some have yet to recover.
The change for the better was intentional and occurred in the mid-20th century. In the 1930s, a joint salmon commission was formed between Canada and the United States “for the protection, preservation and extension of the sockeye salmon fishery of the Fraser River system.” After years of study, the Hell’s Gate Fishway was constructed in 1945-1950. The fishways, built along the sides of the river, have a series of internal baffles that greatly slow the water current from that of the main channel. Besides this, the baffles also provide places for fish to rest before continuing their upstream battle. The websites listed below and signs in the Visitor’s Centre have good illustrations of the fish ladders and how they work.
Congratulations to Mr. and Mrs. Yeniharmen for their FTF while caching in their home province.
TO LOG THE CACHE
Log your visit to Hell’s Gate and also send me your answers to the following questions by clicking on the "Message this owner" above.
1. On the wall opposite the Airtram’s lower station exit/entrance, is a directional sign. This sign also gives the river’s water depth, in feet. How deep was the water on the day of your visit?
2. Describe the water depth as you observe the river within Hell’s Gate. For your reference point, use such things as the fish ladders and the rock walls.
3. From the bridge, observe the up-stream river as it passes through Hell’s Gate to the down-stream river. In your observations, consider the river’s channel widths and the water’s eddies and whirlpools. What conclusions did you make regarding the river in the two places?
4. The cache description states that “People have made changes to their surroundings from the beginning of time: sometimes for the better, sometimes for the worse.” In a sentence or two state what you learned about protecting our environment and the need for protecting it.
5. Optional: As you travel to or from Hell’s Gate, leave the highway (or stop beside it where safe) somewhere from Boston Bar to a bit below Hope, to observe the river. State where you stopped and compare that location to Hell’s Gate. For comparison, note such things as river’s channel width and the water’s relative flow-rate in the two locations.
6. Optional: Post a photo from your experience at Hell’s Gate.
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REFERENCES
Planning Your Trip
Hell's Gate Airtram. http://www.hellsgateAirtram.com
Two Scientific Studies on the Geological Past
Andrews, Graham D.M.. Pleistocene reversal of the Fraser River, British Columbia https://www.researchgate.net/publication/233779821_Pleistocene_reversal_of_the_Fraser_River_British_Columbia. 2012.
-- Includes maps and other illustrations.
Read, Peter Burland. The Geology of the Fraser Valley between Hope and Emory Creek. https://open.library.ubc.ca/cIRcle/collections/ubctheses/831/items/1.0053058. 1957.
Hell’s Gate History and the Salmon
Fraser Valley Distance Education School https://www.fvdes.com/sites/default/files/Hells%20Gate%20FT%20History.pdf
-- Includes good historic images of the Hell’s Gate area
Hells Gate Slide http://www.yorku.ca/anderson/geog3010%20fw14-15/hells%20gate%20slide.pdf
-- Includes good historic images of the Hell’s Gate area
Pacific Salmon Commission https://www.psc.org/about-us/history-purpose/our-history/
-- Includes good illustrations
Book
Lamb, W. Kaye (ed.). The Letters and Journals of Simon Fraser: 1806-1808. Dundurn Press, 2007.