Mount Rainier and Liberty Cap Elevation Survey 2025

TL;DR

This study updates Mount Rainier's summit elevation and icecap status, revealing significant melting trends and predicting future changes to the mountain's highest point based on recent measurements and ice melt rates.

Contribution

The paper provides the first detailed 2025 elevation and ice thickness measurements of Mount Rainier's summit and icecaps, and models future melting to predict when peaks will lose their ice cover.

Findings

Columbia Crest is no longer the highest point on Mount Rainier.

Liberty Cap will lose its ice cap by 2041 and melt to bedrock by 2047.

Recent melt rates are approximately -0.27 m/year for Columbia Crest and -0.49 m/year for Liberty Cap.

Abstract

In 2024, we discovered that Columbia Crest, the historical summit of Mount Rainier, was no longer the highest point on the mountain. Instead, a point 133 m (436 ft) to the south along the southwest rim (SW Rim) was determined to be the new highest point on Mount Rainier. The Columbia Crest icecap melted down 6.64 m (21.8 ft) since 1998. A nearby peak, Liberty Cap, melted down 8.02 m (26.3 ft) since 2007. For this report, updated elevation measurements were taken in late summer 2025 of Columbia Crest and Liberty Cap. Columbia Crest melted an additional 0.37 m (1.2 ft) and Liberty Cap melted 0.67 m (2.2 ft) over the last year. To understand how Mount Rainier's summit may continue to evolve, we used ground-penetrating radar (GPR) to measure the thickness of the Columbia Crest icecap and Liberty Cap. As of 2025, ice is approximately 2 m - 5 m (6.6 ft - 16.5 ft) thick near the summit of Columbia Crest and 10 m - 13 m (32.8 ft - 42.7ft) thick near the summit of Liberty Cap. Using recent measurements by our team and other surveyors, melt rates for Columbia Crest have been -0.27 m/year (-0.9 ft/year) since 1998 (R squared = 0.990) and -0.49 m/year (-1.6 ft/year) for Liberty Cap since 2007 (R squared = 0.998). Based on the elevation of the nearest high-elevation visible rock, Liberty Cap will lose its status as an ice-capped peak by 2041. Assuming recent rates of change continue, it will melt to bedrock by 2047. Columbia Crest is already no longer the highest point on Mount Rainier, and it will likely melt to bedrock by 2045. As of 2025, our results indicate that the summit of Mount Rainier on the SW Rim is at an elevation of 4391.04 m (14406.3 ft +/- 0.1 ft) (NAVD88).