The Northrop SM-62 Snark was an early intercontinental range ground-launched cruise missile that could carry a W39 thermonuclear warhead. Though the Snark was in training by the United States Air Force's Strategic Air Command from 1958 through 1961, it was only deployed as an operational missile for less than a year during 1961. It represented an important step in weapons technology during the Cold War. The Snark was named by Jack Northrop and took its name from the author Lewis Carroll's character the "snark". The Snark was the longest range surface-to-surface cruise missile ever deployed by the U.S. Air Force. Following the deployment of ICBMs, the Snark was rendered obsolete, and it was removed from deployment in 1961.

Project Mastiff, to create a missile for delivery for an atom bomb began immediately after the existence of the atomic bomb was revealed. Due to protracted security concerns of the Manhattan Project involving details of arming, fuzing, and detonating systems Project Mastiff was thwarted by security inhibitions invoked by the atomic weapons program. The Army Air Force's Project Mastiff became a years long "Fiasco" Despite the failure of Project Mastiff the Army Air Force started a group of programs intended to create atomic bomb carrying missiles.

During the significant first decade of American strategic missile development the Air Force's attention was upon developing winged air-breathing missiles. The designations for individual programs changed numerous times due to changes in organizations, roles, fashion, and thus they are best known by their MX numbers. Following the end of WWII the Guided Missile Committee decided that the development of guided missiles should be shifted from the existing ad hoc programs in order to concentrate upon basic research. Northrop was selected to study two concepts, the sub-sonic MX-775A Snark, and the super-sonic MX775B Boojum. Defense budget cuts of what was called the "Black Christmas" of 1946 drastically reduced the number of Army missile programs. Few of those programs which survived resembled the later missiles which they eventually produced. Following the creation of the US Air Force in 1947 winged missile development was transferred to the USAF. In March 1947 the MX-775B Boojum supersonic 5,000-mile range and not the subsonic MX-775A Snark was the only Northrop program. By March 1948 the MX-775A Snark was the preferred missile while the super-sonic MX-775B Boojum had been reduced in importance to a speculative prospect. Further intense budgetary pressure in 1949 saw the USAF surface to surface missile program reduced to two programs of which one was the MX-775A Snark. By July 1950 the Snark program was further reduced to development of the guidance subsystem and creation of a guidance test vehicle. The guidance test missile was the Northrop N-25. Development of the heavy stellar navigation system intended for the N-25 Snark was very difficult and required many hundreds of hours of flight aboard aircraft. Twenty-one flights of the N-25 missile occurred at Holloman AFB, New Mexico between April 1951 and March 1952.

A new requirement for intercontinental range required a new, larger missile the design of which was deemed the B-62. The Northrop N-69 development vehicle, was originally powered by a J71 engine and in later variants a J57. Development missiles were equipped with landing skids to reduce program costs. While 10 of 25 N-25 missiles were recovered, only 11 of 39 N-69s were recovered. As the available space for tests of an intercontinental ranged missile did not exist at Holloman, testing was moved to the Atlantic Missile Test Range at Cape Canaveral, Florida. Test Snarks were recovered to a runway at the Joint Long Range Proving Ground which is still known as the "Skid Strip". Facilities at Cape Canaveral were still being constructed and at the same time aerodynamic problems with the intended dive by the Snark on the target persisted, delaying development.

The Snark, which was originally projected to become operational in 1953, suffered a protracted test program which involved significant redesigns. Development of the Snark dragged on with many failures which caused wags to jest of the "Snark Infested Waters" off Cape Canaveral. As the prospective operational date of the Snark slipped continuously into the future, Strategic Air Command (SAC) grew more skeptical of the missile. Criticism of the Snark grew from doubts by SAC in 1951 to serious objections in 1954. A high-level study by the Teapot Committee in early 1954 described the nascent Atlas ICBM project as beset by technical and administrative problems while advising that the ballistic missile offered the best means of delivering a thermonuclear weapon over intercontinental range. Also in early 1954 the Strategic Missile Evaluation Committee concluded that the Snark was an "overly complex" and would not become operational until "substantially later" than scheduled.

The failure of the Snark to achieve the necessary accuracy for the original W-8 nuclear weapon (striking within 1,500 feet (460 m) of target) was offset somewhat by the change to the much more powerful W-39-Y1 Mod 1 thermonuclear bomb (striking within 8,000 feet (2,400 m) of target). Extensive flight testing, weight reduction efforts, an improved 24 hour stellar navigation system, and the addition of pylon fuel tanks below the wings to restore range capabilities eventually resulted in the N-69E Snark which became the prototype for the SM-62 Intercontinental Missile (ICM)

By late 1957 N-69E Snarks had complete two flights down range to Ascension Island, showing the Snark achieved an estimated circular error probable (CEP) of 17 nautical miles (31 km; 20 mi). By 1958, the celestial navigation system used by the Snark allowed its most accurate test, which appeared to fall 4 nautical miles (7.4 km) wide of the target. However, even with the decreased CEP, the design was notoriously unreliable, with the majority of tests suffering mechanical failure thousands of miles before reaching the target. Other factors, such as the reduction in operating altitude from 150,000 to 55,000 feet (46,000 to 17,000 m), and the inability of the Snark to detect countermeasures and perform evasive maneuvers also made it a questionable strategic deterrent. A total of 97 N-25, N69 and SM-62 Snarks tests were made between December 1950 and December 1960. SAC then changed requirements to require the launch of 20% of Snarks within 15 minutes of notification, 40% within 75 minutes, and all in four hours. A daunting requirement given the base design and requirements of the missile.

In late 1957 SAC's 556 Strategic Missile Squadron launched its first N-69E to begin the Snark Employment and Suitability Test program. In December 1957 the 556th Strategic Missile Squadron was activated and began training to launch operational SM-62 Snark Missiles. In January 1958, SAC began accepting delivery of Snark missiles at Patrick Air Force Base for training, and in 1959, the 702d Strategic Missile Wing was formed. Snark launches for developmental purposes continued through 1958 but the training activities of the 556th were reduced. Training of Snark missile men at the Cape continued until December 1959.