Initial construction was carried out over the winter of 1903–1904, largely using locally obtained materials including lodgepole pine and rhyolite stone.

[3] In 2007 the American Institute of Architects conducted a survey to determine the 150 favorite buildings in America; the Old Faithful Inn ranked 36.

The Old House is rotated 90 degrees with respect to Old Faithful so that a view of the geyser is framed by the entrance porch for arriving visitors.

Both interior and exterior framing is supported by twisted or curved branches, giving the entire structure a strongly rustic air.

Stairs climb from the second balcony to a platform in the framing known as the "Crow's Nest" which once was used by musicians to entertain guests, then on to the crown of the gable 92 feet (28 m) above the lobby floor.

The entire structure is crowned by a roof walk that once held searchlights to illuminate Old Faithful Geyser at night.

[8] Custom ironwork, most notable in the main entrance door and the clock, was forged at the site by an ironmonger named Colpitts.

[6] Most of the logs came from a location about 8 miles (13 km) south of Old Faithful, where a temporary sawmill produced boards as needed.

Stone came from the Black Sand Basin and from a site along the road to Craig Pass about five miles (8 km) to the east.

Some furniture at the Old Faithful Inn was salvaged from the Canyon Hotel before it was demolished, particularly the Limbert chairs in the dining room extension and some of the reading desks on the balcony.

The building was partially shaken loose from its foundations, and access to some of the upper levels had to be restricted due to safety concerns.

In celebration of the Inn's centennial in 2004, a major renovation project of the original "Old House" started construction, with completion in 2008.

The project brought the Inn to current building codes and installed new electrical, plumbing, and heating systems, as well as structural upgrades.

Wood and wool floor finishes, bathroom tile and fixtures, new replica historic hardware, and an interpretation of the original lavatory stands and basins by Charles Limbert were installed.

According to park lore, a freak blizzard struck the Old Faithful Inn on August 25 sometime in the early twentieth century.

[6] In 2007 the Old Faithful Inn was selected as number 36 on a list of the 150 favorite buildings in the United States in a poll by the American Institute of Architects.

The Lodge, which was designed by Gilbert Stanley Underwood to provide dining and guest services to a community of tent cabins, is lower and more understated in nature, but compatibly rustic.