What was the biggest race there?
Probably the August, 1964, USRRC.
The track opened in Sept. 1958 with an SCCA Regional, won by Chuck Daigh in a Scarab. 1959 had three big races, all professional USAC Road Racing Division events. The first two, in May and July, were won by Jim Jeffords in the Nickey Scarab. The Sept. pro race was taken by Augie Pabst in the Meister Brauser Scarab.
1960's biggest race was an SCCA National in July, also won by Pabst in the Scarab.
1961 had a similar schedule, with the July SCCA National the biggest event of the year. This race had a stellar turnout, as this was during the infamous SCCA-USAC war period when SCCA suspended a number of its top drivers for running in USAC events. Somehow or other the Milwaukee Region got by with inviting all the suspended drivers to run as "guests". Many did, and a great race resulted. The winner was Roger Penske in a Maserati T-61, who pressed leader Peter Ryan mercilessly, finally forcing him into a mistake on the last lap. Penske finished just ahead of the Sadler Mk V driven by Ryan. Following were Pabst, 2.5 Ferrari; Bill Wuesthoff, Porsche RS-60; Fred Gamble, Maserati T-61; Dan Shaw, Sadler Mk V; George Reed, Ferrari 250-TR 59; Bob Donner, Porsche RS-61; Pete Harrison, Lister-Chev; and a mess of more Porsche Spyders and other exotica. A memorable race.
1962 had a similar schedule also. The SCCA National was won by Harry Heuer in the Meister Brauser Chaparral 1 after Alan Connell's leading Cooper Monaco T-57 broke its gearbox with only a few laps to go. The Porsche RS-60s of Bill Wuesthoff, Ernie Erickson, and Lee Hall followed, with MRJ Wyllie fifth in a Lola Mk I and Wayne Burnett sixth in a Ferrari 250 Testa Rossa (#0714, just sold for an incredible amount of money).
The 1963 SCCA National was again taken by Harry Heuer in the Meister Brauser Chaparral 1. This year he led the race start to finish. Bill Wuesthoff was second in his Porsche RS-60 with Don Devine third in the Meister Brauser Scarab. Bob Holbert took fourth in a Porsche RS-61 with Lee Hall fifth in a Porsche RS-60 and Dick Doane (yes, Doane's corner was named after him) sixth in a Corvette Grand Sport.
One big race in 1964, the above mentioned USRRC event. Great field, many big names. Ed Leslie was on the pole in a Shelby American Cooper-Ford T-61. The win, though, went to Jim Hall in a Chaparral 2, with Roger Penske second in a second Chaparral 2. Dick Thompson was third in Dick Doane's McKee Chevette, George Wintersteen fourth in a Cooper-Chev T-61, while Ken Miles was fifth overall in the same Cobra 289 with which he won the morning's 120 mile GT race. Under two liter cars followed, with Joe Buzzetta, Bill Wuesthoff, and Ralph Treischmann 6-7-8 in Elva Porsches. Besides Leslie, DNFs included Bobby Unser in the Arciero Lotus 19, now with a Chevy V-8, Skip Hudson in the Nickey Cooper-Chev T-61, and Al Unser in the Arciero Lotus 23 with a 2.0 liter Climax four.
Things tailed off markedly after that. Essentially, only club racing ran at the track from 1965 through the track's demise in 1969. One exception was in July, 1968, when a Trans Am race was held, won by Mark Donohue in a Penske Camaro.
There was an occasional USAC stock car race, details of which I do not know as I did not follow them. Also a drag race may have been held on the long front straight. Perhaps Zooom or Ron can fill us in there.
Tom