Redstone Castle, National Register mansion in Redstone, Colorado.

Redstone Castle is a three-story timber-frame mansion of 42 rooms and 24,000 square feet, built in a simplified Stick style on rough-cut local sandstone. Its west front faces Highway 133 above the Crystal River, with a three-story octagonal tower and conical roof at the southwest corner, a walled terrace, a cobbled courtyard and four tall stone chimneys. The English-style Great Hall has 18-foot ceilings and a sandstone fireplace carved with Osgood's lion coat of arms.

John C. Osgood, founder of the Colorado Fuel and Iron Company, built the mansion as the centerpiece of Redstone, a planned company town meant to improve on typical Western mining camps. After Osgood lost control of the company, prosperity faded within a decade; he returned in the late 1920s to die there. The house was listed on the National Register in 1971, the first property in Pitkin County to be so designated.

The interior displays European antiques and decorative pieces from designers like Gustav Stickley and Louis Comfort Tiffany, reflecting early 20th-century American luxury. These collections shape the character of the rooms you walk through today.

The property operates as a hotel today and offers regular guided tours through its historical rooms, allowing visitors to view the original furnishings and layout. Plan extra time to notice the many design details and craftsmanship techniques built into each space throughout the building.

A peephole set into the Great Hall ceiling let Alma Osgood watch arriving women guests and adjust her own dress before receiving them. The hall's three brass globes, decorated with lions, pineapples and angels, were designed by Louis Comfort Tiffany.