The first Pikes Peak Hill Climb was promoted by Spencer Penrose, who converted a narrow carriage road into the wider Pikes Peak Highway. The inaugural 1916 race awarded the Penrose Trophy to Rea Lentz with a time of 20:55.60; in the same year Floyd Clymer won the motorcycle class with a time of 21:58.41. In 1924 the final Penrose Trophy was awarded to Otto Loesche.
In the years following the early races, Glen Schultz and Louis Unser shared a rivalry and won the event twelve times between them. Following World War II, Louis Unser continued to excel at Pikes Peak, winning three more times between 1946 and 1970 in competition with rival Al Rogers. During this era the event was part of the AAA and USAC IndyCar championship. In 1953, the Sports Car Club of America sponsored the event, bringing with it an influx of sports cars; the course record was broken every year from 1953 until 1962 — the largest consecutive record-breaking streak in the event's history — with the majority set by Louis's nephew Bobby Unser.
The event remained largely an American affair until 1984, when Norwegian rallycross driver Martin Schanche (Ford Escort Mk3 4x4) and French rally star Michèle Mouton (Audi Sport quattro) became the first Europeans to compete. Mouton achieved the overall victory and course record of 11:25.39 the following year in 1985. In 1987, Walter Röhrl won the overall race in the Audi Sport quattro S1 with a time of 10:47.85. The 1988 event was immortalised by the short film Climb Dance, capturing Finnish World Rally Champion Ari Vatanen as he won in a turbocharged Peugeot 405 Turbo 16 with a record-breaking time of 10 minutes and 47 seconds.
Originally a mix of gravel and paved sections, the Pikes Peak Highway was gradually paved between 2002 and 2011 following a court order stemming from a lawsuit brought by the Sierra Club over erosion damage to downstream ecosystems. During the transitional period, Japanese driver Nobuhiro Tajima with Suzuki cars scored six overall victories between 2006 and 2011, including the first sub-10-minute run in 2011.
The first fully paved event in 2012 attracted over 170 racer registrations by December 2011, compared with only 46 at the same point the previous year. The asphalt transformation dramatically raised speeds across all classes. In 2013, World Rally Championship legend Sébastien Loeb shattered the nine-minute barrier with a time of 8:13.878 in the Peugeot 208 T16 Pikes Peak, a record that stood for five years.
Electric vehicles have featured at Pikes Peak on and off since the early 1980s, but became increasingly competitive after the course was fully paved. In 2015, Rhys Millen took overall victory in an electric car; by 2016 electric machinery regularly occupied the podium. In 2018, French driver Romain Dumas completed the course in the all-electric Volkswagen I.D. R with a time of 7:57.148, breaking both the overall record and the 8-minute barrier for the first time, surpassing Loeb's mark by over 15 seconds.
Motorcycle competition at Pikes Peak has had an intermittent history since the event's founding in 1916. Motorcycles only contested the race in 1916, 1954–1955, 1971–1976, and 1980–1982 before becoming an established annual division in 1991, after a new staggered-wave start system vastly improved safety. The gradual paving of the course shifted the competitive advantage toward road-biased sport motorcycles and away from the motocross and flattrack machinery that had dominated earlier.
Four-time winner Carlin Dunne became one of the event's most celebrated motorcycle competitors, setting the first sub-10-minute motorcycle time on a Ducati Multistrada in 2012. On 30 June 2019, Dunne was killed in a crash less than a quarter of a mile from the finish line while riding a prototype Ducati Streetfighter V4. Following review after the 2021 event, the organisation discontinued motorcycle competition permanently. The fastest motorcycle time on record is 9:44.963, set by Rennie Scaysbrook on an Aprilia Tuono V4 during the 2019 event.
The race is self-sanctioned and features a diverse selection of machinery across multiple divisions. The Unlimited Division allows any vehicle passing safety inspection and attracts the most exotic purpose-built machines with the greatest chance of setting overall records. Other current divisions include Time Attack 1 (production-based vehicles), the Porsche Pikes Peak Trophy by Yokohama (exclusive to the Porsche Cayman GT4 Clubsport), Open Wheel (traditional single-seaters ranging from Indy-style sprinters to dune buggies), the Pikes Peak Open (production-based with unlimited modifications), and an Exhibition Class for vehicles demonstrating motorsport technology advancements.
The Pikes Peak International Hill Climb stands as one of the oldest motorsport events in the United States, predating most major European hillclimbs still active today. Its unique combination of extreme altitude, dramatic elevation gain, and ever-changing high-country weather has made it a singular proving ground for automotive technology. The transition to a fully paved course in 2011 transformed it from a mixed-surface endurance test into a pure outright-speed contest, enabling successive leaps in lap records that have positioned the event as a benchmark for electric vehicle performance at the highest level of motorsport.