Point plotted at the Lombard Ferry Oregon Train Interpretive Center 

Located 15 miles from Big Timber Station and 20 miles from Ham’s Fork Station on the west bank of Green River above the mouth of Big Sandy Creek. McCarthy was Station Tender. 

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

Key sources generally agree on the identity of Green River as a station, near an early fording area of the river.  Green River served as a home station for both the stage lines and Pony riders.  Richard Burton discusses the Green River Station at great length in his travel journal.  http://www.nps.gov/parkhistory/online_books/poex/hrs/hrs6a.htm#87