What do Jaws, a three-year bike tour from Alaska to Argentina in the seventies and Missoula’s Adventure Cycling have in common? They’re all celebrating 50-year anniversaries, and they’re all connected to Montana.
June and Greg Siple were the first cyclists to bike from Alaska to Argentina during the Hemistour Bicycling Expedition. The cascade from that three year tour changed biking in America. Listen for conversations with the Siples, Dan and Lys Burden – the Siples’ companions on the Hemistour – and Jessica Zephyrs, vice president of marketing and communication with Adventure Cycling.
Fifty years ago, a National Geographic writer was asked to go to Oregon for a story. There were some people doing a huge bike packing trip and the magazine was interested enough to send a writer along for a week or so to put a piece together on the adventure. The writer first asked, Peter Benchley, declined – he was working on a book about fish. Sharks, to be precise. That book would ultimately provide inspiration for the movie Jaws.
At an event at The Historical Museum at Fort Missoula this summer, an audience member at June and Greg Siple’s presentation about that bikepacking trip remarked that the Siple’s lives would have been so much different if Benchley had joined them on the Hemistour Bicycling Expedition, or the Alaska to Argentina bike ride, that the Siples completed in 1975, just over 50 years ago. They were the first cyclists to do so.
“Just think how famous you could have been,” a man attending the presentation said to June and Greg.
“And you’ve been probably noticing this is the 50th anniversary of Jaws,” June said.
While it may not have reached Jaws-level, nationwide paranoia, the Hemistour made its mark. The reason Nat Geo wanted to send a writer to cover the Hemistour – after learning about it from photos Greg took and sent to the magazine – was because it was novel. So much so that the writer who did accompany the Siples, Noel Grove, coined the term bikepacking.
Between 1965 and 1975 was largely considered the bike boom for adult bicycling. At its height, more bikes were sold than cars in 1972, 1973 and 1974 in America.The catalyst for the sixties boom was in large part due to the creation of the Schwinn Sting-Ray bike and other wheelie bikes that brought cycling to a wider audience with their bigger wheels and more upright seating position, as opposed to that more flat-backed stance associated with road cycling. Ten-speed bikes became more affordable and versatile during the boom era, too. The Hemistour is nestled right into the boom, and it isn’t a stretch to associate it with the legacy the bike boom left behind.
What the 18,272-mile ride accomplished is still seen and felt today – it introduced America more generally to long-distance biking. The Hemistour led to the mapping of the first transcontinental American bike route eventually dubbed the TransAmerican Trail, from Virginia to Oregon, that over 4,000 people rode as part of an event called Bikecentennial in 1976. That event, celebrating its 50th in 2026, led to the creation of Adventure Cycling, a nonprofit based in Missoula, Montana. Through its evolutions, Adventure Cycling can claim creation of that first map of theTransAmerican Trail.
Adventure Cycling carved a niche for itself making maps of bike routes and serving as a hub, particularly in Missoula, for those choosing to travel and adventure via bike.
Listen for conversations with the Siples, Dan and Lys Burden – the Siples’ companions on the Hemistour and eventual key organizers in the Bikecentennial – and Jessica Zephyrs, vice president of marketing and communication with Adventure Cycling.
Visit this landing page for more bonus content including interviews with Hemistour riders and photos from the adventure.