USAC opened their season at Ontario with a 200-mile race on March 6. A. J. Foyt won the race over Al Unser. That same day, Foyt finished third 3rd in the USAC Stock Car race at Ontario, won by Jimmy Insolo.
In May, A.J. Foyt won the 1977 Indianapolis 500, becoming the first man to win the race for a fourth time.
Practice began on Sunday, August 28. Defending California 500 champion, Bobby Unser was fastest at 190.496 mph.[2] In Monday's practice, Johnny Rutherford was fastest at 193.440 mph. Rutherford had a close call when Chuck Gurney spun as Rutherford came up to pass him in turn one. Rutherford was able to squeeze between Gurney's spinning car before he backed into the wall. Gurney suffered a slight concussion.[3]
Rutherford was again fastest on Tuesday with a speed of 197.425 mph. Two days after competing in the 1977 Dutch Grand Prix, Mario Andretti began practicing, and posted the second fastest speed at 194.363 mph.[4]
Pole Day - Wednesday August 31
Qualifying was a four-lap, 10-mile run. Johnny Rutherford won the pole with a four-lap average of 195.111 mph. Late in the afternoon, Mario Andretti made a run at 194.900 mph, good enough to claim the second position. Al Unser completed the front row with a speed of 194.774 mph. Joe Saldana and Phil Threshie had separate crashes in turm one on their qualifying runs. Both cars were too damaged to be repaired and withdrew from the race.[5]
Bump Day - Thursday September 1
In the second and final day of qualifying, Danny Ongais posted the fastest speed of all cars in the field at 196.389 mph. Ongais blew an engine on Wednesday morning and was unable to make a qualifying attempt on Day 1. Because his run came on day 2, he started the race 20th.
Late in the qualifying session, 32 cars had qualified for the race, meaning there was one vacant position. Jerry Sneva attempted to make a qualifying run, but was black-flagged for leaking oil. He returned to pit road and got in the qualifying line behind Bob Harkey and Eldon Rasmussen, who had lost a cylinder in practice. As time expired, Bob Harkey went onto the track to begin his qualifying run. He seemingly was assured a spot in the field, regardless of his speed, since there was still one spot open. On his second lap, Harkey's engine blew and he was unable to complete his run. USAC determined the final starting spot by random drawing: Harkey, Sneva, or Rasmussen. Rasmussen was the lucky winner and earned the 33rd starting spot for the race.[6]
Race
Actor James Garner drove the Datsun 280Z pace car. The crowd was estimated at 70,000 spectators, the highest crowd in many years.[7]
From his position in the middle of the front row, Mario Andretti took the lead at the start. On lap three, Dick Simon retired from the race with a burnt piston.
Steve Krisiloff brought out a caution on lap 12 when he came a stop on track. The fastest qualifier, Danny Ongais, climbed from his 20th starting spot to take the leaf when the leaders pitted under caution.[8]
On lap 76, Janet Guthrie broke a hose clamp and entered the pits. While there, she turned her car over to teammate Dick Simon, who was eligible to earn points as a relief driver.[9] "I owe Dick a lot. He's done many favors for me. I was glad to be able to repay him a little." Guthrie then flew to Darlington, South Carolina where she competed in NASCAR's Southern 500 the next day. Simon continued until lap 113 when he blew an engine and spun.[10]
Mike Mosley made his return to IndyCar racing after suffering a concussion and whiplash in a crash at the Pocono 500 in June. Near halfway, Mosley left his pits after a routine pitstop and his car caught fire. He stopped in the Patrick Racing pit stall and jumped out of the car as the fire was extinguished. Mosley returned to the race 12 laps down, but retired after 135 laps due to engine failure.[8][10]
By halfway, the race appeared to be a battle between Al Unser, Danny Ongais, and Gordon Johncock. Johncock took the lead on lap 152 and had extended his advantage to 17 seconds.[8] Running third with 36 laps remaining, Ongais ran out of fuel on the backstretch. The caution was waved to retrieve his stalled car. Ongais lost eight laps due to the miscue.
The caution bunched up the leaders. With 24 laps remaining, Johncock held a slim one car-length lead over Unser. Entering turn one, Johncock lost control and spun out, lightly hitting the wall.[11]
Unser was unchallenged after Johncock's crash. He led the final 25 laps and won his first California 500 by 46 seconds over A.J. Foyt. Tom Sneva finished third and clinched the 1977 USAC Championship. Mario Andretti finished fourth. Seven days later, Andretti won the 1977 Italian Grand Prix. 11 of the 33 starters finished the race.[7]
