This is the picture called Westward Ho!  by, Emanuel Leutz, 1826-1868.

I had a hard time finding images of the beginning on the trail. I have cobbled together some pictures that somewhat give an idea of what it must have been like to start this 2,170 journey.
They had to ford rivers and the difficulty of that depended on how much rain there had been. They did climb mountains. The end of the trail had mountains and they had a hard time.
The pictures are mainly from Wikipedia Commons. The pictures from the National Archives and Record Administration is shortened to NARA.
I’ll start with the maps.

Oregon Trail Map  by, National Park Service

NASA Topographical Map with the Oregon Trail drawn by Matthew Trump.

The next map is of the Missouri River. They did cross it. It is the longest river in North America. The drawing of the river is done by Matthew Trump.

Another map. This one is covers the area covered by the Missouri River. It is by, the US Army Corps of Engineers.

Pictures of the Missouri River in Missouri and Kansas.

At St. Joseph, Missouri  by, Tim Kiser

At Great Bend, Kansas City, Boston Public Library

Also from the Boston Public Library, a picture of the Kansas Plains.

The covered wagons usually were four feet wide and twelve feet long. They were narrow because of the trail they had to travel. a wide wagon wouldn’t have been able to get through some spots.
The wagons weighed about 1,000 pounds.
Wagon trains had from 50 to 100 wagons in them.
The canvas covers were tightened down on rainy days to keep the supplies dry.

By, Verne Equinox

By, John B. Homer, Wikipedia

By, Eleanor Stackhouse from the How and Why Library

From the US Bureau of Land Management

Oregon Trail Reenactment  from, NARA

Wagon Train  by, unknown photographer

Wagon Train  by, National Park Service

The next picture is of Breaking up Camp at Sunrise  by, Albert Jacob Miller.

The last picture is of making camp at the end of day  by, Albert Bierstadt 1830-1902.