Denali today, whose height was first calculated by Bradford Washburn at 20,320 feet. (Photo by David Merz)

Denali today, whose height was first calculated by Bradford Washburn at 20,320 feet. (Photo by David Merz)

Refuge Notebook: Bradford Washburn — an early explorer’s use of aerial photography over a century of exploration, science

Editor’s Note: This is the second part of a series the Kenai National Wildlife Refuge is doing on the history of remote sensing and aerial photography for Refuge Notebook.

Bradford Washburn’s historic mountaineering and mapping expeditions in the far north of Alaska and the Yukon are legendary. He helped lead the way for future scientists that use remote sensing and digital cartography in their work today, as we do here at the Kenai National Wildlife Refuge.

Bradford Washburn was an American explorer, mountaineer, aerial photographer and cartographer who climbed, photographed (aerial photography) and mapped mountain ranges in Alaska, Canada and the Himalayas. He summited Denali three times and pioneered the first ascent of the West Buttress climbing route, a favorite of climbers today.

Barbara Washburn, his wife, accompanied him on many of these expeditions and was the first woman to summit Denali. He was the first to take aerial photographs of Denali and several other mountain peaks and glaciers across Alaska and the Yukon.

Washburn also recalculated the heights of Denali and Mount Everest and created detailed topographic maps of both mountains. His surveys of the Grand Canyon produced one of the first large-scale maps of the interior of this magnificent canyon.

Most of his expeditions were supported by the National Geographic and the Museum of Science in Boston, where he was museum director for 41 years.

In 1935, Washburn led the National Geographic Yukon Expedition, the first successful traverse of the St. Elias Range from the Yukon Territory to Alaska.

The expedition aimed to map this mountain range and its glaciers using aerial photography and land surveying methods that required summiting several peaks throughout the range. The three-month-long trip was in late winter, and Washburn’s team spent nearly all that time on the ice.

On this expedition, Washburn experimented with using planes and aerial photography for reconnaissance of the routes his team used to map the mountain range. He made special modifications to the aircraft by removing the cabin door and installing a rope system to tie himself to so he could lean out the side of the plane with his K-8 Fairchild camera and snap photos of the mountains below.

Dressed in heavy winter clothing, he braved frigid temperatures at altitudes between 12,000 and 18,000 feet for hours at a time while conducting these aerial photography flights.

After successfully traversing, mapping and naming several mountain peaks and glaciers on the Yukon Expedition of 1935, Washburn returned to the St. Elias Mountains in 1937 on another expedition. It became one of Washburn’s most challenging adventures because of the dangerous survival situation he and Robert Bates found themselves in during the trip.

On this expedition, Bob Reeve, a famous Alaska Bush pilot, piloted a Fairchild 51 plane mounted with skis so he could drop Washburn and Bates off on the Walsh Glacier in the St. Elias Mountains. After a 3-hour flight from Valdez, Reeve successfully landed on the glacier.

However, before they could unload all the climber’s supplies, the plane sank to its belly in glacial slush because of the unseasonably warm temperatures. They tried frantically to dig the plane out, but all three ended up marooned on the glacier for five days.

After conditions improved, Reeve was able to get the aircraft off the glacier after reducing enough weight, but that meant leaving behind Washburn and Bates. They were stranded in one of the most remote mountain wilderness areas in North America with no one to rescue them, and low on food and supplies.

Washburn and Bates traversed nearly 100 miles of uncharted, rugged terrain living off squirrels and rabbits to return to civilization. Despite their survival situation, they were still determined to make the first ascent of Mt. Lucania on their trek out and were the first mountaineers to summit Mt. Lucania’s 17,192 feet.

In 1936 and 1937, Washburn took the first large-format aerial photographs of Mt. McKinley. At high altitude and in freezing conditions Washburn and his flight crew used oxygen above 15,000 feet to capture photos of this lofty peak.

This trip led to future expeditions in the 1940s and 1950s that involved first-time achievements in aerial photography, mountaineering and mapping North America’s highest peak. In his work, Washburn summited the mountain three times in 1942, 1947 and 1951.

In 1953, after several years of surveying Denali, Washburn estimated a new height for Denali at 20,320 feet. The current height of 20,310 feet was established in 2015 using the latest GPS survey methods.

Then, in 1960, Washburn produced, for the first time, a detailed topographic map of the mountain known as the “Map of Mt. McKinley.” Many cartographers consider it a masterpiece, and mountaineers and scientists still use it today and will continue to for years to come.

In the 1970s, Washburn and his wife took on another large-scale mapping project. They spent the next seven years surveying and mapping the Grand Canyon. Before he started this survey work, he ordered two sets of aerial photographs from 26,000 feet and 16,000 feet that covered the entire canyon to get an aerial view of the project.

The Washburns spent the next several years surveying the canyon using the latest laser surveying technology and helicopters to access the most remote parts of the canyon. In 1978, National Geographic published the 1:24,000 scale topographic map, and to this day, it is still considered a cartographic work of art among mapmakers.

Washburn never quit exploring, photographing and mapping the wilderness landscapes he loved. In his 70s, he took on one of his final aerial photography and mapping projects that required all the skills, leadership and ingenuity he had acquired over years of leading and organizing remote scientific expeditions.

By the time of this trip in 1980, aerial photography and land surveying technology had advanced considerably since Washburn’s early excursions. This time around, he wanted to capitalize on new technology to map the world’s highest peak, Mt Everest.

After lots of negotiation and planning, he received permission from the governments of Nepal and China to make several photographic mapping flights over the mountain. These high-altitude flights took vertical mapping photos from an altitude of 39,000 feet.

He planned to use aerial photos from those flights and infrared images from the Columbia Space Shuttle (taken 156 miles above the earth) to create a detailed topographic map of Everest. After years of work and with the help of a team of international scientists, the National Geographic Society published one of Washburn’s finest topographic maps.

Using the latest GPS technology at the time, he and his team recalculated a new height for Mt. Everest at 29,035 feet.

Washburn’s career spanned almost a century, and he received numerous awards and honorary doctorates for his scientific accomplishments in Alaska and around the world. You can learn more about Bradford Washburn and his extraordinary expeditions through his National Geographic articles, journals and his autobiography, “Bradford Washburn: An Extraordinary Life.”

Through the early aerial photography and mapping work of explorers and scientists like Bradford Washburn, we continue to use aerial photography and other remote sensing techniques to understand the changing environmental conditions in places like the Kenai National Wildlife Refuge.

In Part III of this series, I will be writing a brief history of how aerial photography and cartography saw considerable technological advancement after the Second World War, and the use of aerial photography and cartography in natural resource management in Alaska.

David Merz is a seasonal biological science technician on the Kenai National Wildlife Refuge who is part of a team using aerial photography and remote sensing to understand changing environmental conditions on the Kenai NWR and throughout Alaska.

Bradford Washburn’s maps produced by National Geographic. (Photo by David Merz)

Bradford Washburn’s maps produced by National Geographic. (Photo by David Merz)

More in Sports

ski tease
Kenai sweeps Tsalteshi ski meet

The Kenai Central High boys and girls teams both placed first last Friday.

tease
Homer boys basketball tops Nikiski

Homer will host the annual Winter Carnival basketball tournament this weekend, starting Thursday.

Flanked by JDHS freshmen Manu Adams, left, and Paxton Willoughby, right, Homer junior Berend Pearson looks for a pass from a teammate. The Crimson Bears and the Mariners faced off at the Treadwell Arena in Juneau following the Bears’ senior night ceremony on Friday, Jan. 23.<ins>, 2026</ins>
Juneau hockey celebrates senior night with sweeping victory over Homer

The Crimson Bears saw an 8-2 victory over the Mariners Friday night.

Ninilchik's Austin White puts down a two-handed dunk against the Aniak Halfbreeds Wednesday at the Class 1A state basketball tournament at the Alaska Airlines Center in Anchorage. (Photo by Joey Klecka/Peninsula Clarion)
Sports briefs: SoHi boys top Kenai, Eagle River in shootout

The Soldotna varsity boys came out 2-1 in the Al Howard Shootout last weekend.

tease
Homer boys, Soldotna girls place 1st in ski invitational

Soldotna’s Tania Boonstra took first place for the girls’ division, leading her team to victory at the meet. The Homer girls’ varsity team placed second overall.

Senior Mason Bock exclaims after winning the state title during the ASAA Division I state championships in Anchorage, Alaska on Dec. 20, 2025. Bock beat No. 2 seed Isaiah Schultz of Colony High School in the final, securing his victory in the 135-pound title as the No. 4 seed. Bock said standing on the podium was the best moment of his life, telling the Clarion that since he had lost to Schultz once earlier in the season, he was “focused and determined to have a different outcome” during the final match. Photo courtesy of Andie Bock/Andie’s Alaskan Adventures Photography
SoHi girls 3-peat at state wrestling championships

The boys team placed second and saw five wrestlers win state titles in the Division I tournament.

Seward’s Atlin Ryan wrestles against a Mountain City Christian Academy athlete during the regional Kachemak Conference Wrestling Championships on Saturday, Dec. 13, 2025, at Homer High School in Homer, Alaska. (Delcenia Cosman/Homer News)
Homer girls wrestling team named regional champions

Kenai boys, girls both placed third overall in the Kachemak Conference Wrestling Championships on Saturday.

The Soldotna High School wrestling team is pictured after the Northern Lights regional conference in Wasilla, Alaska, on Saturday, Dec. 13, 2025. SoHi sent 33 boys and 11 girls to regionals. 22 boys and nine girls will compete in the state tournament at the Alaska Airlines Center this weekend. Photo courtesy of Soldotna High School Athletics
SoHi wrestling wins regional title; 31 wrestlers advance to state

22 boys and nine girls will compete in the state tournament this weekend.

Homer and Soldotna hockey players battle for the puck during the Carlin Cup home varsity game on Saturday, Dec. 13, 2025, at the Kevin Bell Arena in Homer, Alaska. (Delcenia Cosman/Homer News)
SoHi hockey claims 3rd Carlin Cup victory

The Soldotna varsity hockey team defeated Homer 9-1 Saturday at Kevin Bell Arena.

Sophie Tapley is photographed with her parents, Josh and Whitney Tapley, during Sophie’s signing ceremony at Kenai Central High School on Nov. 26, 2025. Tapley committed to playing volleyball at the University of Alaska Anchorage during the 2026-2027 school year. Photo courtesy of Jesse Settlemyer, Kenai Central Athletics
Kenai Central’s Sophie Tapley signs with UAA volleyball

Tapley will trade her Kardinals jersey for a Seawolf one during the 2026-2027 academic year.

Photo courtesy Pete Dickinson
The SoHi junior varsity and varsity wrestling teams compete in the Battle for the Bird at Soldotna High School on Wednesday, Nov. 26. The Kenai Peninsula Athletics Sapphire dance team performed the halftime show.
SoHi, Nikiski wrestling teams compete for Thanksgiving dinner

The Stars and Bulldogs faced off during the Battle for the Bird duals last Wednesday.

Runners of all ages gather for a photo in the Homer High School Commons after the annual Thanksgiving Turkey Trot on Thursday, Nov. 27, 2025, in Homer, Alaska. Due to icy outdoor conditions, the official run was moved to the high school halls. Photo courtesy Matthew Smith
55 turn out for Homer Turkey Trot

Each Thanksgiving morning, the Kachemak Bay Running Club and the City of… Continue reading