Union Oil Center, 1923-1965

1956, New Union Oil Building, completed in 1958.  Thanks to Getty Images and Classic Hollywood/Los Angeles/SFV.

1923, 617 West 7th Street, Los Angeles, CA.  This was the Union Oil Headquarters until the Union Oil Center was completed in 1958. 

Looking east on Seventh Street past the Union Oil Building, Los Angeles, California, early to mid-twentieth century. (Photo by Dick Whittington Studio/Corbis via Getty Images)

1933, Union Oil Building, Los Angeles, CA.

1940, Union Oil Building, 7th and Hope Street, Los Angeles, CA.  Thank you to Getty Images. 

1952, a bond certificate for Union Oil of California.

1957, probably 1958 since that is the year the Union Oil Center was completed.

The Union Oil Center was built by the Phoenix-based Del E. Webb Construction Company—known for its work on The Beverly Hilton and the Flamingo Las Vegas, hired by Bugsy Siegel himself—which completed it in 1958 (a year after the city height limit had been repealed). 

And that's where the former Union Oil Company of California chose to build its LA headquarters, known as Union Oil Center (and after 1983, as Unocal Center). Thank you to AvoidingRegret.

1959, Union Oil Corporation.  It chose the architectural firm Pereira and Luckman—the partnership of William Pereira and Charles Luckman, with Gin Wong (who appropriately designed the 76 gas station in Beverly Hills a decade later)—to build a campus in the International style, which would provide "modern utility with architectural beauty."

1965, Union Oil Research, Brea, California in Orange County. 

https://thegetty.tumblr.com/post/92659285065/the-union-oil-center-was-completed-in-1958-and

1922, Oil derricks part of Union Oil field in Santa Fe Springs.  

Overall, Santa Fe Springs, at the time of writing, was producting 700,000 barrels per day with about 120 new wells underway.  Hill stated that “in point of prolific production, high gravity oil and proven area this field is considered by many to be a contender for first place in the California oil fields.”