Not least among the achievements of the late Les Richter was the re-introduction of Indy car racing to Riverside International Raceway in 1981, a move which paved the way for Indy cars to replace Formula 1 at Southern California's most prominent racing event.
Situated on the edge of the desert east of Los Angeles, Riverside had served as a host venue for Indy car racing (and once even for F1) until the Ontario Motor Speedway, a clone of the Indianapolis Motor Speedway, opened some 25 miles up the freeway in 1970. Ontario dabbled in road racing with an infield course, but the two venues soon settled into serving different audiences. Ontario hosted a pair of Indy car weekends a year, the latter forming the final leg of the Triple Crown of 500-mile races. As the 1970s ended, however, Ontario faced oblivion as mounting debts forced its sale, and the new owners made it clear they were more interested in the facility's value as an industrial park site than as a racetrack.
Amid this crisis came opportunity. CART, having recently gained control of the sport from USAC, was at that time in the process of expanding Indy car racing's oval-centric schedule to include a wider variety of road racing venues, and so an offer from Riverside, then managed by Richter, to relocate Ontario's traditional Labor Day weekend California 500 to the 3.1-mile RIR permanent road course for 1981 was eagerly accepted. Swapping miles for kilometers enabled the magic “500” name to be retained, but 300-plus miles of racing in the desert in late summer brought its own set of challenges in the form of 105-degree temperatures and brutally smoggy air quality. Even so, a record crowd estimated at 52,000 packed Riverside's Spartan grandstands for the inaugural race.
Geoff Brabham, drafted in by Dan Gurney for this race to drive his stock-block Chevy V8-powered Eagle, took pole with a lap 1.5sec faster than the next-quickest car, despite being some 75hp down on the Cosworth DFX turbo-engined cars that predominated in CART's lineup. Brabham easily outdistanced them in the race as well, until a stripped thread on a wheel nut during a pit stop cost him five laps. Al Unser then took over at the front in his Williams FW07-based Longhorn chassis before he, too, retired with mechanical problems. Into the breach came Rick Mears, whose smooth style was ideally suited to the grueling conditions. Mears' Penske PC9B motored to victory over Gordon Johncock's Wildcat by a more than one and a half minutes.Mears scored again at Riverside the following year in a race that played out almost exactly the same way: His Penske teammate Kevin Cogan took pole and dominated early, only for his Cosworth to go up in smoke in the triple-digit heat. Mario Andretti's fast Wildcat met a similar fate, and the more patient Mears had no one left to race with.
By the time of its third visit in 1983, CART's drivers, cars and teams were more adept at road racing's driving and endurance challenges, and Bobby Rahal had to outduel rookie star Teo Fabi in a straight fight for the win. By then, though, CART was looking beyond Riverside to the more munificent – and cooler, in both senses of the word – seaside street course in Long Beach, which had booted F1 in a dispute over sanction fees. The improved road racing form Indy cars had shown at Riverside helped convince Long Beach race founder Chris Pook to take a gamble on CART for 1984, and Riverside fell off the Indy car calendar once again.
RIR continued to play host to sports car, NASCAR and off-road races until 1989 when it, too, fell victim to Southern California's insatiable land development thirst and was paved over for a shopping mall. But Les Richter was quickly on to the next challenge, serving as the point man for Roger Penske a few short years later in the transformation of a derelict steel mill property in Fontana – practically within view of the old Ontario track – into California (now Auto Club) Speedway.