Operation HIGHJUMP, officially titled The United States Navy Antarctic Developments Program, 1946–1947 (also called Task Force 68), was a United States Navy mission to build the Antarctic research base Little America IV. Rear Admiral Richard E. Byrd, Jr., USN, served as Officer in Charge of Task Force 68, and Rear Admiral Ethan Erik Larson, USN, was Commanding Officer of Task Force 68. Operation HIGHJUMP began on August 26, 1946, and concluded in late February 1947. Task Force 68 included 4,700 personnel, 13 ships, and 33 aircraft.

Operation objectives

HIGHJUMP was a large-scale mission designed to test long-term operations in the polar regions. Its main goal was to build a base called Little America IV on the Ross Ice Shelf and to test how well ships, planes, and ground teams could work together in Antarctica. The mission also aimed to take many aerial photos and collect data about water, weather, and other scientific information to help map Antarctica and choose future base locations. Additionally, HIGHJUMP tested navigation, communication, and air operations in high-latitude areas to support national security and showed the United States' presence in regions where others might claim ownership of land.

HIGHJUMP’s stated goals included:

• Teaching people and testing ships, planes, vehicles, clothing, fuels, and repair methods in Antarctica’s extreme conditions.
• Studying the cost, difficulty, and risks of setting up and running bases in Antarctica, and finding suitable locations for future bases.
• Creating and improving methods for building and using air bases on snow and ice, including preparing runways, flying planes with skis, and maintaining equipment in cold weather, with a focus on future use in Greenland.
• Taking detailed photos and maps of Antarctica’s coasts and inland ice, and expanding knowledge about electromagnetic, geological, geographic, water, and weather conditions.
• Increasing the United States’ claim to the largest possible area of Antarctica, though this goal was not officially stated before the mission ended.
• Supporting tasks related to Operation Nanook, a smaller mission conducted near eastern Greenland.

Timeline

The Western Group of ships arrived at the Marquesas Islands on December 12, 1946. The USS Henderson and USS Cacapon established weather monitoring stations there. By December 24, the USS Currituck began sending aircraft on missions to gather information about the area.

The Eastern Group of ships reached Peter I Island in late December 1946.

On December 30, 1946, the Martin PBM-5 George 1 crashed on Thurston Island, resulting in the deaths of Ensign Maxwell A. Lopez, ARM1 Wendell K. Henderson, and ARM1 Frederick W. Williams. The other six crew members were rescued 13 days later. These individuals, along with Vance N. Woodall, who died on January 21, 1947, were the only people who died during Operation HIGHJUMP.

On January 1, 1947, Lieutenant Commander Thompson and Chief Petty Officer John Marion Dickison used "Jack Browne" masks and DESCO oxygen rebreathers to complete the first dive by Americans under the Antarctic. Paul Siple was the senior U.S. War Department representative on the expedition. Siple was the same Eagle Scout who had traveled with Byrd on earlier Antarctic expeditions.

The Central Group of ships arrived at the Bay of Whales on January 15, 1947, where they began building Little America IV.

Naval ships and personnel returned to the United States in late February 1947. The expedition ended because winter was approaching and weather conditions worsened.

Byrd shared lessons learned from the operation in an interview with Lee van Atta of International News Service. The interview took place aboard the expedition's command ship, the USS Mount Olympus. The interview was published in the Wednesday, March 5, 1947, edition of the Chilean newspaper El Mercurio.

After the operation ended, a follow-up mission called Operation Windmill returned to the area to verify information from HIGHJUMP's aerial photography between 1947 and 1948. Finn Ronne also funded a private expedition to the same region until 1948.

As with other U.S. Antarctic expeditions, people were allowed to send letters with sealed envelopes to the base. Commemorative cachets were added to the envelopes, which were then returned to the senders. These special envelopes are now available for purchase at low prices. It is estimated that at least 150,000 such envelopes were created, though the actual number may be higher.

Participating units

Rear Admiral Richard H. Cruzen, USN, in charge

Capt. George J. Dufek, USN, in charge

• Seaplane Tender USS Pine Island. Capt. Henry H. Caldwell, USN, in charge
• Destroyer USS Brownson. Cdr. H.M.S. Gimber, USN, in charge
• Tanker USS Canisteo. Capt. Edward K. Walker, USN, in charge

Capt. Charles A. Bond, USN, in charge

• Seaplane Tender USS Currituck. Capt. John E. Clark, USN, in charge
• Destroyer USS Henderson. Capt. C.F. Bailey, USN, in charge
• Tanker USS Cacapon. Capt. R.A. Mitchell, USN, in charge

Rear Admiral Richard H. Cruzen, USN, Commanding Officer

• Communications and Flagship USS Mount Olympus. Capt. R. R. Moore, USN, in charge
• Supplyship USS Yancey. Capt. J.E. Cohn, USN, in charge
• Supplyship USS Merrick. Capt. John J. Hourihan, USN, in charge
• Submarine USS Sennet. Cdr. Joseph B. Icenhower, USN, in charge
• Icebreaker USS Burton Island. CDR Gerald L. Ketchum, USN, in charge
• Icebreaker USCGC Northwind. Capt. Charles W. Thomas, USCG, in charge

Rear Adm. Richard E. Byrd, Jr., USN, (Ret), Officer in Charge

• Aircraft carrier and flagship USS Philippine Sea. Capt. Delbert S. Cornwell, USN, in charge

Capt. Clifford M. Campbell, USN, in charge

• Base Little America IV

On December 30, 1946, aviation radiomen Wendell K. Henderson, Fredrick W. Williams, and Ensign Maxwell A. Lopez died when their plane, named George 1 (a Martin PBM Mariner), crashed during a blizzard. Six crew members survived and were rescued 13 days later, including aviation radioman James H. Robbins and co-pilot William Kearns. A plaque to honor the three men was later placed at the McMurdo Station research base. Mount Lopez on Thurston Island was named in memory of Ensign Maxwell A. Lopez. In December 2004, an effort was made to find the plane’s remains. In 2007, a group called the George One Recovery Team tried but failed to get military help or raise money from the United States Congress to locate the bodies of the three men who died in the crash.

On January 21, 1947, Vance N. Woodall died during a "ship unloading accident." In a crew report, deckman Edward Beardsley said his worst memory was "when Seaman Vance Woodall died on the Ross Ice Shelf under a piece of roller equipment designed to 'pave' the ice to build an airstrip."

In media

The documentary The Secret Land was made by military photographers from the US Navy and US Army. It was spoken by actors Robert Taylor, Robert Montgomery, and Van Heflin. The film includes Fleet Admiral Chester W. Nimitz talking about Operation HIGHJUMP with admirals Byrd and Cruzen. It showed scenes of important events, such as fixing damage on a ship and Admiral Byrd throwing objects out of an airplane to make it lighter and avoid hitting a mountain. The film won the 1948 Academy Award for Best Documentary Feature Film.