More for the list or to look into -
Ascot Municipal GC - Los Angeles - 18 holes in the infield of the Ascot Speedway.
Tampa Bay Hotel GC - a small practice course existed within the racetrack while the new 18 hole course was being laid out.
American Jockey Club at Arlington Park
Lincolnshire CC aka Lincoln Oaks GC - built in connection with Lincoln Fields racetrack.
Kansas City Jockey Club aka Elmridge CC
St. Louis Jockey Club
New York Jockey Club - at the site of the Morris Park racecourse, which hosted both the Preakness and the Belmont
Allegheny CC in Pittsburgh started from a group that played out of the Homewood racetrack.
Vancouver GC (WA) - plans for a course to be laid out on the site of an old racetrack, no evidence course ever built.
The course in the infield of the Harlem racetrack in Chicago was also the location for Newspaper GC and Tecumseh GC.
In addition, there were a great number of golf and automobile clubs, many of which might have had some kind of racetrack.