I actually knew a guy who searched that area south of temple by the leon, lampassas, little river Y, He"s dead now and dident find it.
I have now heard of 3 possible locations stephanville (posted by anoldpro) sangabriel (I forget the sight I got that info) and the link posted by oklahunter.
I do know this, Bryant station was around the temple location and was a ranger fort as well as a settlement established by Benjamin Bryant, he was a Texas revolution survivor and recieved his land as payment for the independence. So rangers would have had a close base to work out of if the fight took place south of temple.
Dallas area (and anywhere north of the brazos, This includes Bryant station) would have been very bad Indian territory at that time, If the rangers were that far north in 1839 (stephenville)They would have been days tracking the party, and would have needed a pretty big group to stay safe from the Indian threat. (also consider the rangers had a reputation of being some B.M.F.) Of course The ranger article could be wrong about him burying the gold there.
I would love to get whatever info you might have on the subject AnOldro.