The fantastic story of the Bonneville Flood: a catastrophic megaflood from ~17,400 years ago 

As an archaeologist, I have surveyed much of the Bonneville Flood topography in southern Idaho. Spent several decades working in the Snake River Canyon around Auger Falls, the canyon near King Hill, and surveying powerline corridors across the Eden Channel basalt north of the canyon. The Bonneville Flood dominated much of my work since 1988. I currently live along the Snake in Owyhee County. Your presentation is a really good summation of what took me years to gather and added to my knowledge. Thank you.

I always tell people as men get older they start looking into geology and geography... Very good production thank you sir

Thank you for covering this! I'm a rock climber, and I go bouldering in Swan Falls every weekend. I'm always in awe of the force required for a body of water to move such large boulders.

It is mind numbing to think that such a huge lake is gone. As a former trucker I drove through those places; was always awed by what was once there and what is there now.

Absoutely captivating! The powers of water and gravity are astounding. As a kid I used play for hours in sand and use a garden hose to flood the little lakes I made. The erosion patterns you show on the map remind me of these childhood memories but blown up to an apocalyptically massive scale.

I live on the Fort Hall Indian Reservation, and I work for a farmer during harvest. He has some fields that are very sandy. If you look toward Pocatello from those fields, this is where the water flow would probably have started to slow and turn west. All of the new housing being put in place over the last couple of years in Chubbuck, is plagued by river run boulders the are sometimes as big as a small car. It is just 6 miles further that you find these very sandy fields. The Farmer has other fields that are about the same distance from Pocatello, but are further east, and these fields are no where near as sandy. I can see the things that you are describing as I travel around this area. Thank you for making this video. I always thought that Lake Bonneville went clear from Salt Lake City to Reno. I was shocked to learn that all of these years I was 100% wrong.

in my undergraduate days in Trinity College Dublin, I learned of the "parallel roads of Glenroy" in Scotland. They were one of the great mysteries of Victorian Britain; parallel lines around the valley sides following the contours. Eventually explained as shorelines of a lake hemmed into the valley by a glacier, the same as you discuss in this video. A great presentation. Thank you.

Amazing story! My husband and I live at the base of Y Mtn. in Provo, Utah and the Bonneville Shoreline which has been made into a fabulous hiking/biking trail is right up the mountain from us. The higher shoreline isn’t as easy to see close up, but if you come around the Point of the Mountain just before I-15 goes downhill southward into Utah County you can clearly see it. I wasn’t aware that the Bear River once flowed into the Snake River. You make geology so fascinating and accessible. Many thanks.

It was actually your excellent vids like this one that drew me to your channel, as I try to learn more of the geology around Ogden where my parents moved in the 90s. I love how the ghost of lake Bonneville seems to reappear every now and then when there's a weather inversion, capping fog or haze at the level of the bench.

I thought I'd read a lot or watched a lot of videos about Lake Bonneville, but none of them mentioned the rerouting of the Bear River. Thanks to RU-vid randomly recommending your video about the Great Unconformity I also discovered this one. I live in Utah and have spent a little time in the West Desert, seeing the Bonneville shorelines, but now I'd love to travel the path of the Bonneville flood to see some of these areas in person. Thanks for the engaging content!

I traveled through the southern region of Boise with an old military buddy I was visiting who lived in Boise years and years ago. It was something to see all of those giant rocks in person and wonder where they all came from. I read the information about the flood off of signs and other postings around the area, but seeing it here explained in so much more detail really makes the sheer size of the event come across. Thanks for all of the work to share this information with us!

I grew up visiting grandparents in Pocatello and fishing the Portnuef and Snake Rivers. Also crossed Utah on the salt flats over to Bonneville. Stopped at Twin Falls to view the Snake River Canyon last year. Your presentation has helped pull together the saga that only vaguely was known after years wandering the region. Thanks for your work.

I used to hike in Melba, Idaho overlooking part of the Snake river, at the end of this flood and the boulders there are huge and the landscape as a result of it is so incredible.

Great video as usual. Your work means a lot to those of us who are learning some geology on our own. Thanks a lot.

I knew about Lake Bonneville, but had no idea how it drained until last week when listening to RadioWest's story about Utah Lake. Thanks for illustrating this because I was really amazed to learn that this was such a sudden event.

I've watched this a few times now because I think is extremely intriguing and I'm fascinated that someone a long time ago figured this out and then along comes someone like you to eplain it on video and can share it on something like RU-vid... After the first time I watched this one I came across some other youtubers that try to explain this; no one even comes close to the level of detailing this as you do.

I thought I commented before now. One of my favorite topics/videos. Lake Bonneville does not get enough attention for such a powerful story. Thank you.

Marveled for forty years at the Self declaring story of Lake Bonneville. But I never knew till now how and why it drained. Never knew about the Bear River getting diverted into it, and how that affected its growth and size. Geology of the last glacial age is so cool !!

Dude, this was awesome. Life long resident of southern Idaho and have noticed these formations. Thanks for the great explanation!

My wife grew up a few miles south of Red Rock pass. We loved teaching our kids about the lake. I grew up in Utah County and hike the Bonnivel Shoreline trail. This is a very informative video. Thank you.

This is fantastic. I am from Central Utah and I see the lasting effects from Lake Booneville in my area. It is jaw dropping to think of how much power this flood generated. Thank you for making this.

great job on this! Best presentation on the Bonneville flood I've seen

I grew up in Twin Falls. Always knew about the flood but not to this extent. This is such a great lesson. Thanks

Really great account Shawn. I would love to see a similar portrayal of the catastrophic post-glacial flood events that happened in my area along the Ottawa River, Ontario, Canada. During deglaciation, a vast melt water lake breached it's eastern boundary through Fossmill Outlet, then other catastrophic floods occurred down the Ottawa River when the southern outlet of the same glacial lake (the outlet being the Mississippi River) became plugged. The flow features from these floods are interesting to see in the bush. Vast sand plains throughout the Madawaska, Bonnechere and Petawawa River valleys are other features from these floods.

Thank you. What an interesting video. We passed through Twin Falls and marveled at the Shoshone Falls and that huge park. Seeing it here, it was a tiny part of the entire Bonneville Flood event. Thank you again.

I’ve never heard of this flood until I visited the Bruneau Sand Dunes! Amazing to see (and feel) in person! I still don’t understand it all…the tallest dunes in North America, right there! Yet the geology changes back to farmland once leaving.

I lived in Brigham city. On the mountain above Brigham had some of the shoreline’s. You can still collect small sea shells. It’s pretty amazing it’s at least 2-3000 feet above Brigham. Brigham city is at 4200 feet elevation. Thank you for the video. Have a wonderful day..!!

Thank you for putting this video out there. I have been to every single place you mention many times over the years, except for Celebration Park. Now I'm going to have to visit is for the rocks and the petroglyphs. Your information helped me put all of this into perspective and explained how they came to be. I also love knowing how everything from the seemingly insignificant Bear river contributed to the rise of Lake Bonneville, then to the undoing of Lake Bonneville, the Higher benches, and to the deepening of the Snake River canyons going to Twin Falls and beyond. Very fascinating.

Just watched a presentation on the USGS channel about massive landslides that happened in southern Utah millions of years ago and I’m struck at the awesomeness of these huge events. I enjoyed this presentation and am glad to have a medium like RU-vid to learn of these things.

As an undergraduate in the 70s I did fish population sampling along the White River of Nevada. It dried up about 17,000 years ago I guess and left a series of relic fish populations behind in warm springs in isolation along it’s old path. A lot of speciation occurred over the years.

Great Job. I have traveled these areas extensively and am quite interested in the Geology of Areas. I knew about the Bonneville Flood, but had not heard any details that came close to what you offered. Thank you.

I lived in southern Idaho for about a year. Great place, great scenery, and great people. Thank you for bringing me back!

amazing story about the flood, thank you for putting it out there for us, i really enjoyed it

I didn't know about the Eden Channel. Thanks!

Very fascinating I lived in Utah for 18 years and was always impressed with all of the geological features. I now live New Mexico and would like to learn more about the geology of New Mexico and understand why the south west is so barren and understand the typography better of the desert southwest. I really enjoyed the video thank you for the information.

Thank you for this unbelievable page in our history 🌿

I remember when mainstream geologists laughed to scorn the very notion of catastrophism. I, however, remember a guest lecture given by an elderly professor emeritus who was something of a catastrophist. He convinced me (primarily a cultural geographer). The Bonneville Flood, of course, proves the concept. I believe that there probably are ample other examples on the landscape, if only we could recognize them.

Having learned some geology and geomorphology in geography, years ago at school, (I always enjoyed the maps bit more than the chaps bit!) I realised recently the joy I have experienced through the many years trying to interpret the scenery through which I have travelled. It’s only later that you realise what a gift that your favourite teachers give you.

Every time I fly across the continental divide I am riveted to my window to see the geographical features and imagine what must’ve transpired to form them.

Looking down upon the inversion clouds from the Wasatch, the "ghost of lake Bonneville" is visible. Thank you for the trip through time. Makes driving around the west much more interesting.

Fantastic Geo-Story Telling.

Great job on explaining the Bonneville Flood and its effects in Idaho. It is unfortunate that most people are seeing the lower resolution version since the higher resolution version is much better.

Very well done, Shawn. It answered a lot of questions as my wife and I have extensively studied and explored the full length of the Missoula Flood evidence. Will spend time now looking at the Bonneville Flood evidence, thanks for your comprehensive story.

Thank you for this program!

Shawn, very informative video and story of Bonneville Flood and Red Rock pass. I remember reading about Red Rock pass in high school geography, but no other details. Glad to learn more. Thank you.

So cool! I've heard about this so much but never seen it laid out to understand it all. Also didn't know about the bear river diversion... That was new info. Is there a good reference site for great basin lake maps? I've often wanted to study shoreline maps of the different periods and levels.

Wow! I learned so much with this discussion. Thank-you.

This was a great presentation. I love geology and geography. Thanks. Makes me want to take a trip.

Gives me a new perspective to view that landscape the next time I pass through there. Thanks for that presentation.

Great presentation! My roots are in Cache Valley so I have wondered about this story for decades as I would see the bench marks on the mountains.

Thank you for this concise discussion. Having grown up in Salt Lake City, I’m fascinated by the geology of that region and how blessed my ancestors and I were to live there when the landscape was more primitive and the population density much less than it is now. It’s harder to appreciate the landscape now, but I still think of Utah and Arizona as God’s country and wouldn’t care to be anywhere else.

Great job. I appreciate your hard work to bring us such a great video.

I live on the Snake River just downstream from Celebration Park. I knew about Lake Bonneville but this added much more detail to the flood story... thanks.

Thank you, good work, I appreciate your effort.

Wow! Great job! Now I’m going to go check for more from you, sir!

Very informative, Thank you. I drove through the area years ago and had to stop every few miles to explore. Disappointed that there wasn't more info online, but your video answered many of my questions.

I can't imagine what it might have looked like to stand at that gap on top of the nearby mountains and watch the flood unfold. It must've been terrible. I drive through that gap all of the time. Its fascinating how the Bear River got dammed up by the lava flow and then diverted into the Great Salt Desert area. I didn't know that all of the those benches where they built todays sub-urbs in the Salt Lake City area were a result of the huge lake that created those shelves, some of them 500- 1,000 feet higher than todays lake levels.

Nicely done. Fascinating. Thank you

Fantastic presentation! Thanks for all you do 🙂🌊

Not sure, why this came up on my recommended but I’m glad it did! This is interesting!

Thanks, great job. So glad you cleared up if the snake river canyon was created by the flood. I grew up in Kimberly and heard that myth my whole life.

Fascinating and so well explained. Thank you! We had a nice hike at Celebration Park today, so viewing your presentation tonight was timely.

This was so amazing to learn!

I was wondering what the cataclysmic drainage of Lake Bonneville did to the landscape. Many thanks!

Hopefully you’ll do a story on the historic Lake Missoula Flood too. This was great!

Fascinating, thank you. I had heard of the flood but never so much details.

Great presentation! Thank you very much.

👍 content! Was watching on my TV, and became frustrated with the 360p resolution. Came to my phone to comment and noticed you've uploaded a higher res version. My TV RU-vid app didn't show the link but I noticed it in your video description. Makes a big difference!

Lived in Burley in the late 70's. With backyard on Snake River and a treehouse over the river.

Well presented and quite interesting. Thank you!

Thank you for the video, enjoyed it.

Thank you. I had heard of this flood in a video about the floods from glacial lakes Missoula and Agassiz and wanted to know more about Bonneville.

This was great! We didn’t learn much about this when I was in school and I grew up in Utah. Great job!

Thank you! Very good presentation 👏

This was fantastic. Thank you

been picking up rocks for 70 years and like yourself still love the discovery of unraveling the stories they tell and the landscapes they shape-well done

Great presentation of great event. You make it so easy to understand such an almost incomprehensible event!!! Thank you !

thank you for making this video! I have driven I-84 in Idaho many times and knew that Bonneville Flood had helped shape the Snake River valley, but did not know what to look for. Now, the next time I need to make that drive, I will have your book in hand to see the signs of the flood.

You are a good person and you are making a difference by doing good, Thank you!👍🏻❤️

Love it when unusual and interesting videos like this show up on my feed. That was an excellent presentation, clear and with lots of change in visual style to keep it interesting.

Good presentation. This is something that was not touched on at all when I was studying geology back in the early 1970's.

I loved that presentation.

loved it, thanks

Thank you Shawn. Very informative and interesting.

Thank you very much for this presentation. We’ve been living in the Pocatello area for 3 years, but did not grow up here, so we did not know much about these events. It is vary interesting.

very clearly explained. thanks.

Wow. You are amazing. Thank you.

that was fantastic. What an exciting story of the earth. Thanks so much for your excellent teaching.

Excellently done. Subscribe button smashed.

I really liked the video. Very well done and very well researched. I grew up in Bear River City at the bottom of Lake Bonneville and have for the past month been driving through Red Rock Pass almost daily commuting to a job so it's very interesting to me The scene at 3:44 the top half shows what is called Little Mountain which was the scene out my bedroom window as a kid. Looks just like it always did. THANK YOU!

Excellent talk!

Being from the Northwest I have heard (and know) a lot about the Missoula Floods, but I had no idea of the Bonneville Flood (heard of the lake, just not the flood that it produced). That is really interesting, thanks for sharing.

Very cool. Great collection of information and well explained and displayed.

Thanks Shawn. Great presentation on a subject that's always caught my interest. Just subscribed! Growing up in Idaho Falls in the 1960s a sign on Highway 20 north of town always amused me... "Tourists - Do not laugh at the natives". That and your petrified watermelon sign were advertisements for a chain of gas stations called Stinker Stations.

I grew up in Burley and always in awe of boulders everywhere... This should be taught in schools

Thank you so much for this video. It really helped me to understand this flood I'd heard about growing up. I've never understood why the Bear River turned and went toward the Great Salt Lake. I live outside of Pocatello and have two boulders in my back yard and my yard is full of gravel when I dig. Now I know why!

Good show Shawn, I find historic geology extremely interesting. I enjoyed your presentation very much. Thank you for sharing your knowledge! Jim

Really great !

This was great!!

You kept this old gals attention all the way through. Thanks for the education.