"Were the cars on the Hooper turn standard gauge cars? If they were it appears they may have used a standard gauge caboose. It would be an empty, the other empty being the idler car.
I was wondering about the spring rush as well."
The cars on the Hooper turn appear to be standard gauge as they came from Douglas Wyoming and no re-load point is shown. And I would go with the idea the caboose was standard gauge as well.
Yes, there were spring rushes but not the same magnitude as the fall rushes. Some of the ones I personally recall are sheep returning from Utah to the Woody Creek area.
Most of this days stock appear to be headed for market, sheep destined for Kansas City, Mo River, and Denver, cattle for Convoy Iowa, Williamsburg, PA, Mt Vernon Iowa, Kansas City and Fremont, Nebraska. Some sheep also for Eaton and Ault Colorado.
Jimmy