I believe this location is just south of the former Oklahoma State Fairgrounds, on the east side of Oklahoma City, where Douglass High School now stands. Which would put the refinery southeast of the intersection of NE Fourth Street and North Martin Luther King Avenue (former Eastern Avenue). A number of paddock buildings are visible to the southeast of the track. The body of water between the racetrack and the refinery is now part of James E. Stewart Golf Course.

Is for walking and training horses. It is not a railroad roundhouse.

The roundhouse is probably for indoor horse-training. Notice the really big, long building top right of center. That's an aerodrome if ever I've seen one.

[Actually that's the Stockyards Coliseum, aka the Oklahoma City Ice Palace, built in 1922, destroyed by fire in 1930, and then rebuilt with a similar design. - Dave]

Looks like a horse racing track in the background, center, with stables in the background, right.

What's the roundish large building in the background left, with cupola? Railroad roundhouse? Indoor fairgrounds?

[Whatever it is, it is not the same building as the fairgrounds carousel. - Dave]

The only oil company in Oklahoma at the time with "Producing & Refining Co." in their name was the Denver Producing and Refining Company. Most of the remaining information on the company is in the form of lawsuits that were lodged against it in the '30s and '40s.

[This all looks like secondhand equipment, which would explain why the DENVER (Acme, or whatever) was removed from the tank. - Dave]