Rio Grande Pyramid, Mountain summit in San Juan Mountains, Colorado, USA

Rio Grande Pyramid is a mountain summit at around 13,800 feet (4,200 m) in the Weminuche Wilderness, within San Juan National Forest in Colorado. It sits in one of the most remote corners of the San Juan Mountains, surrounded by steep rocky slopes and open alpine terrain above the tree line.

The Wheeler Survey team made the first recorded ascent in 1874 as part of a government mapping expedition through southwestern Colorado. Their work helped establish a more detailed picture of the San Juan range at a time when much of the region was largely uncharted.

The peak's name comes from its position near the headwaters of the Rio Grande, which rises in this part of the San Juan Mountains. The summit lies on an east-west stretch of the Continental Divide, about 25 miles south of Lake City, the Hinsdale County seat. Its 13,827-foot elevation places it among Colorado's highest summits, with more than 500 metres of prominence.

The trail starts at Thirty Mile Campground and covers a long round trip with a steep elevation gain, so solid hiking experience and proper gear are needed before setting out. Starting early in the day is strongly recommended, as afternoon thunderstorms are common in the mountains during summer.

Just below the summit there is a natural opening in the cliffs called The Window, sitting at roughly 13,000 feet (3,960 m). Walkers who pass through it find themselves suddenly looking out over a completely different valley on the other side of the mountain.