Old film movie buffs - does anyone know what the title of this old movie could be?

I watched a really good old movie like from the 20s or 30s a few months ago, it was on either the Western channel or Turner Clic. It was in black and white with sound, 3 guys hold up a bank in an old town like in the 1800s era out in the dessert, they steal gold coins, go to the dessert as they run off bec they shot a banker in the process. They come across a covered wagon with a pregnant lady in it, one of the men helps her give birth, soon after she tells them her dying wish is for them to make sure the baby lives and she dies. The guys are rough and tough types but take care of the baby, one abandons them at night, the other I think died in the desert, the third makes it back to the town where the guy he had shot was the baby's father, makes it to the church barely, dying of heatstroke, gives the town people the baby as they are singing a Christmas carol then the movie ends!!