What river does The Transcontinental Railroad cross 31 times?

From: "Charlie Kirk"

What river does The Transcontinental Railroad cross 31 times?

This was referred to in a The Transcontinental Railroad Almanac:

It took six years and two armies totaling 20,000 men. Many of the workers were immigrants from China and Ireland who sweated long hours for one or two dollars a day. They laid tracks across hundreds of miles of prairie and scorching desert. They pushed over heights of 8,000 feet and tunneled their way through hard mountain ridges, sometimes at a rate of only a few inches per day. They bridged stream after stream. The tracks crossed one river alone thirty-one times. ...

—Charlie Kirk

"China comes to Sacramento to celebrate countrymen who built transcontinental railroad"

"China comes to Sacramento to celebrate countrymen who built transcontinental railroad" by Stephen Magagnini, © Sacramento Bee, May 23, 2015. (News Article)

"China came to Sacramento earlier this month for a gala celebrating the 150th anniversary of a feat that many said couldn’t be done – the building of the transcontinental railroad over the Sierra Nevada. At the May 15 gathering at the California State Railroad Museum, several hundred of the region’s leading Chinese Americans joined Sacramento Mayor Kevin Johnson in welcoming a delegation from the Chinese consulate general in San Francisco to see an extensive photo display featuring murals, figurines and sculptures depicting Chinese railroad workers. The exhibit – including 122 sequential photos depicting laborers, work camps, stores and tunnels blasted through the hardest granite – is open to the public for free at the Sacramento County Administration Center, 700 H St., Monday through Friday from 8 a.m to 5 p.m. through June 19[, 2015]. ... " [More]