Question: In which year did this American pioneering mountaineer and writer, after whom this scattering of glaciers and snowfields located on the southern flank of Mount Rainier in Washington was named, climb Mount Rainier?
Sentence (from "Van Trump Glacier"): Named after P. B. Van Trump, who was part of an early ascent of Mount Rainier, the glacier covers 0.2 sqmi and contains 500 million ft (14 million m) of ice.
Relevant evidence: Yes