Timegate: tales of the saddle tramps (1999)

While visiting a historic Western town, two women (Amy Lindsay and Kim Yates) are transported back in time to the Old West. After being mistaken for new recruits for the local brothel, the women hook up with some cowpokes. But their erotic escapades end up ruffling some feathers, and when the deputy winds up dead, the posse's hot on their tails for answers. Now, they must get back to their own time before they wind up jailed or worse.