Object spewing contrail over SW OKC

I was laying in my hammock on the back porch looking directly West, clear skies, no clouds, sunny evening.  The sun was almost on the horizon and in the distance I could see what looks like a contrail illuminated by light (contrail approximately 45 degrees to horizon).  Seen that a thousand times, but this looked different.  I decided to get my Leupold binoculars and take a look.  It appeared to be a small aircraft but appeared triangular...it was spewing out what appeared to some sort of liquid...as portions of it were clouds but denser portions were dropping...very similar to a plane dumping water over a forest fire...which I have witnessed many times while living in Colorado/NM.  This was different as the craft was climbing vertical as it was spewing this whitish liquid.  The contrail's base was flared and narrowed as it came closer to the craft.  I decided to get my camera w/ telephoto lens.  Went inside to get it...approximately 30 seconds...came back o! utside and the contrail and the object were both gone.  This is the part I can't figure out.  I watched it for about 4 minutes, viewed it for 30 seconds with binoculars, 30 seconds later it disappears.  Never seen anything like this before.  Object appeared to be several miles up.  Rationally I thought perhaps a fuel dump over a populated area?  I just don't know.  Very strange.
Witness elects to remain totally anonymous; provides no contact information.  PD