Philemon Beecher Van Trump was an American pioneering mountaineer and writer who lived in the state of Washington. He is best known for the first documented ascent of Mount Rainier in 1870.

Mount Rainier, also known as Tahoma, is a large active stratovolcano in the Cascade Range of the Pacific Northwest in the United States. The mountain is located in Mount Rainier National Park about 59 miles (95 km) south-southeast of Seattle. With a summit elevation of 14,411 ft (4,392 m), it is the highest mountain in the U.S. state of Washington, the most topographically prominent mountain in the contiguous United States, and the tallest in the Cascade Volcanic Arc.