The range reaches an elevation of 8,295 feet (2,528 m) at Sunday Peak, located just south of Portuguese Pass.

During the Gold Strike of 1854 miners crossing the Greenhorn Mountains founded the town of Keyesville.

[2] The Greenhorn Mountains contain a variety of native California flora and fauna.

One wildflower found here is the Yellow mariposa lily (Calochortus luteus), which is at the extreme southern end of its distribution range.

[3] The Marsh checkerbloom (Sidalcea ranunculacea) is endemic to the range and adjacent Sierra Nevada foothills.