The Gallatin Gateway into Yellowstone National Park
   via the Chicago, Milwaukee & St. Paul Railway

Caption:  The Gallatin Gateway into Yellowstone National Park cutting through the virgin wilderness of the Gallatin National Forest and the spectacular canyon of the Gallatin River. Gallatin Gateway is the wonder entrance to Yellowstone and "The Greatest Gateway" to the greatest national park.

This 1920s-era lavishly illustrated postcard was produced by the Chicago, Milwaukee & St. Paul Railway ("to Puget Sound - Electrified") to promote their branch line to the village of Gallatin Gateway, Montana, where tourists were transported by bus, as seen in this card, into Yellowstone via Gallatin Canyon. This is today's Route 191, which runs through the northwest corner of the park and connects West Yellowstone and Bozeman. The following passage from
Yellowstone Treasures by Janet Chapple explains more:
The Village of Gallatin Gateway is 15 miles (241 km) from Bozeman, just off the highway. As you pass near it, you'll see the restored Gallatin Gateway Inn, built as the terminus of the Chicago, Milwaukee, St. Paul, and Pacific Railroad (nicknamed the Milwaukee Road), which operated a branch line to this inn from 1927 to 1961. In those years, park visitors arriving by train were met at the inn by the classic yellow park concessionaire's buses. (pp. 25-26)
   Shown in this postcard is the Gallatin River, which flows north out of Yellowstone. It is a popular trout fishing stream, and fishing scenes in the movie A River Runs Through It  were filmed on the Gallatin. The log gateway structure shown in this card bears a sign reading "Gallatin Gateway - Yellowstone National Park."