Located 12 miles from Warm Springs Station and 12 miles from Rock Creek Station on east side of Silver Creek. Known by many as St. Mary’s Station. This was a Home Station and William Reid was Station Tender. The site of St. Mary’s Stage Station, also called Rocky Ridge Station because of a cliff near by, is marked with a stone tablet. The station was built in 1859 by Russell, Majors and Waddell, and when the transcontinental telegraph line was established in 1861, St. Mary’s was made a depot. In May, 1865, while the 5-man garrison hid in an abandoned well, 150 Cheyenne and Arapaho burned the station and cut 400 yards of telegraph wire. When the ammunition in the buildings exploded, they fled. The station was rebuilt, but nothing remains except old square-cut nails, melted glass, broken pottery, and pieces of telegraph insulators.

http://www.expeditionutah.com/featured-trails/pony-express-trail/wyoming-pony-express-stations/

The 1861 Overland Mail Company contract listed this station site as Rocky Ridge,  but apparently the station was also known as St. Mary's. Several sources identify Rocky Ridge as a station site. Bishop and Henderson place the station between Warm Springs and Rock Creek, while James Pierson locates it between Rock Creek and South Pass.  Franzwa describes Rocky Ridge as a "desolate" summit in his Oregon Trail maps, but he does not identify any station site there.  On the other hand, Franzwa does list St. Mary's Station in his Oregon Trail maps, but he does not specifically identify the site as a Pony Express stop. He places St. Mary's between Warm Springs Station and Rocky Ridge. Whereas, James Pierson identifies St. Mary's as a station between Three Crossings and Rock Creek.

http://www.nps.gov/parkhistory/online_books/poex/hrs/hrs6a.htm#79