This postcard shows the once-common sight of a bear approaching a passing visitor to Yellowstone Park, and the visitor stopping the car to experience a close encounter with the wild animal. Decades ago, this was not understood to be very dangerous, and over time increasing numbers of visitors were attacked or mauled by bears in such situations.

The caption states:

BEARS ON HIGHWAY

YELLOWSTONE NATIONAL PARK

Long renowned as a refuge for wildlife, Yellowstone contains a wide variety of animals. Most popular and best known are the yellow and brown bears which are frequently seen along the highways through the park.

— In recent decades bears have been relocated to more remote areas when possible to reduce the likelihood of violent encounters with visitors and campers. People are given instructions and training on how to avoid attracting bears to their camps and especially to their food.

The automobile in this picture places the card in the late 1940s.

This postcard shows the suggestively named Mae West Curve, part of the mountain-crossing Highway 12 in Wyoming, as it was then known. The highway as since been renamed US 212, and passes through the mountains west and north of Yellowstone National Park before entering the park from the Montana side.

The caption states:

#4050 – Mae West Curve on the Beartooth Highway (U.S. 12) to Yellowstone Park via Red Lodge and Cook City.

— Mae West was a popular and deliberately provocative actress of the early days of talking movies. Her large breasts were the most noted feature, and Mae West also gave the name to a style of personal flotation device (life jacket).

This card is likey from the 1940s.

This card is a complimentary card provided by the hotels’ management to promote their businesses, located at the time on the Lincoln Highway (U.S. 30) in Rock Springs, Wyoming.

The description states:
TWO FINE MOTELS with 80 Homelike, Quiet, Comfortable Modern Accommodation Units and Tourist Apartment Facilities, Vented Panel Ray Individually Heated, Tiled Tub and Shower Baths, Patio, Play and Picnic Grounds, Separate Truck Parking Lot.
LOCATED IN TOWN ON U.S. 30 EAST
ROCK SPRINGS, WYOMING
SENATOR LOUIS and ROSE BOSCHETTO, Owners
–Neither of these establishments exist today. The card likely dates from the 1940s.

This image shows the Lincoln Highway as it was when it passed around Eagle Rock, Wyoming. This named landform is not commonly described elsewhere other than this card.

The description states:
EAGLE ROCK is a prominent point just east of Evanston on the Lincoln Highway (U.S. 30). The highway diagonally traverses the whole length of the county and is entirely oil surfaced and is so well maintained that overland travel has not been impaired for a single day in recent winters.
–The description does not identify the exact portion of the landform that is supposed to represent an eagle. It may refer to eagles once present there. Instead, it focusses on the nature of then current  US highway construction, replacing more primitive dirt and gravel roads with thin membrane surface, a design now restricted to low capacity secondary roads.
The postcard likely dates from the 1940s.

This is a limber pine tree that was seeded and grew in the crack of an ancient granite boulder, some distance from any similar tree. It was present when the railroad came by in the 1860s.

The description states:
Lone Tree. This Tree, growing out of solid granite is 76 years old. This tree is located on the Lincoln Highway 28 miles west of Cheyenne.
–More commonly called Tree Rock, the monument, little changed in many decades, is now in the median strip of Interstate 80 where vehicles passing by can pull off in the center of the highway to examine the site.
This card likely dates from the 1940s.

This is an image of the well-known volcanic outcrop known as Devils Tower. It became famous most recently when featured as an important plot element and site for the climax of the film Close Encounters of the Third Kind in 1977.

The back of the card is severely damaged, and the description cannot be determined.
The name as shown on the card is misspelled, as the common form uses the plural instead of the possessive, and thus omits the apostrophe.
Colorized photo cards of this type are commonly dated from the 1940s.