Bob, about 20 years ago I was talking to an old timer, he was over 90years old, he told me his Grandfather told him the Elk, in the winter used to migrate out of the mountains in Mexico, to here in the Rio Grande, valley that was before fences. but he is not the only one that has told me Elk, are native to S. Texas.
Never heard of Elk, refereed to as { whistling deer ) interesting. Rio7
Where in South Tx.? The area around Copper Canyon looks Elky and they had Grizzlies until possibly as late as the 1950's no question they were there in the 1850's.