This weekend's upcoming episode of Doctor Who, "A Town Called Mercy", has the Doctor visiting the Wild West for the first time on television since the era of William Hartnell and "The Gunfighters"...
But if you can't wait around until then to check out some Timelord action in a Western setting, might I suggest Peacemaker, the novel I wrote for the 10th Doctor and Martha Jones back in 2007 for the BBC Books imprint.
'The peace and quiet of a remote homestead in the 1880s American West is shattered by the arrival of two shadowy outriders searching for 'the healer'. When the farmer refuses to help them, they raze the house to the ground using guns that shoot bolts of energy instead of bullets...
In the town of Redwater, the Doctor and Martha learn of a snake-oil salesman who's patent medicines actually cure his patient. But when the Doctor and Martha investigate they discover the truth is stranger, and far more dangerous.
Caught between the law of the gun and the deadly plans of intergalactic mercenaries, the Doctor and Martha are about to discover just how wild the West can become...'
You can order a copy from Amazon Here, download it to Kindle, or try the abridged audiobook version read by Will Thorp (who played Toby Zed in the TV episodes "The Impossible Planet" and "The Satan Pit").