Discover The Mills Building in San Francisco
The Mills Building can be found in the heart of the Financial District at 220 Montgomery Street. With one glance you’ll notice that the building seems a little out of place with the rest of San Francisco’s cutting edge sky-scrapers and high-tech innovation. But let’s not forget that at the time of its commissioning, The Mills Building was a pioneer of steel-frame construction—making it one of the city’s first true skyscrapers!
Over the years it has earned its reputation as a survivor, having endured the devastating 1906 earthquake and fire that wiped out much of San Francisco. Today, The Mills Building continues to show off its 19th-century design on the outside, with modern amenities, making it a unique and sought-after office space on the inside. From its iconic Montgomery Street archway to its meticulously restored marble interiors, the building is an architectural gem.
Creating The Mills Building
Early History
Constructed in 1890, The Mills Building emerged during a transformative period in American architecture. Designed by the renowned team of Burnham and Root, this building was one of the pioneering high-rises in San Francisco, embracing the revolutionary steel-frame construction that was becoming the norm during the industrial revolution. This new approach allowed architects to create taller, more resilient structures—and The Mills Building was among the first to showcase the Chicago School style right here in San Francisco.
Architectural Details
Commissioned by (and named after) Darius Ogden Mills, a prominent financier and influential figure in the city’s early economic development, the building was initially 10-storys. One of the building’s most eye-catching features is its Montgomery Street entrance arch, which channels the Richardson-Romanesque style with flair. Adorned with carved acanthus leaves, egg-and-dart moldings, and flanked by pairs of marble Corinthian columns, this grand entryway sets the tone for what lies inside.
Step into the lobby, and you’re greeted by the original curved staircase, still crafted from Jaune Fleuri marble, alongside luxurious touches of black Belgian marble and Roman travertine flooring—a mix that speaks to the building’s rich history and attention to detail.
Structural Ingenuity
Beyond its aesthetic appeal, The Mills Building was designed with functionality in mind. Its "boxed" construction, featuring an iron interior frame supported by exterior masonry piers, was a marvel of engineering at the time. Early challenges, such as the discovery of quicksand during excavation, prompted a clever redesign of the foundation—ensuring stability without sacrificing the building’s elegant proportions.
Overcoming Challenges
Besides structural issues, The Mills Building also faced environmental challenges. In 1906, when the infamous San Francisco earthquake struck, the building suffered severe interior damage and a fire, yet its robust construction helped it withstand the disaster.
Almost immediately after the quake, the building underwent a thorough restoration led by Willis Polk—a prominent architect of the time—who not only repaired the damage but also expanded the structure. This phase of reconstruction included significant additions in 1907, 1914, and 1918, effectively evolving the original design into a more comprehensive and sturdy edifice.
In 1931, the iconic Mills Tower was introduced as an annex to the original building. Designed by George W. Kelham and Lewis Parsons Hobart, Mills Tower further cemented the complex’s status as a major architectural landmark in the city.
Preserving The Mills Building
Over the years, The Mills Building has seen a build-up of impurities accumulating on its exterior. In a bid to restore its original glory, conservation experts stepped in with a detailed survey and cleaning process, meticulously removing layers of grime from the surfaces of the terra cotta, brick, and white Inyo marble, which came from Keeler, California. This careful preservation effort not only unveiled the building’s intricate details but also ensured that its historical integrity remains intact for future generations.
Landmark Status
Today, The Mills Building holds the distinction of being the last remaining example of Chicago School architecture in San Francisco. Recognized as San Francisco Designated Landmark #76 and listed on the National Register of Historic Places, it continues to serve as a hub for businesses ranging from major financial firms to innovative startups. Its prime location, coupled with modern amenities, makes it a coveted address in the Financial District.
Working at The Mills Building in San Francisco
Situated in one of San Francisco’s busiest corridors, The Mills Building provides tenants with more than just a prestigious address. With 24-hour access, a concierge service, expanded bike storage, secure controlled entry, a wellness area with showers and lockers, and on-site property management, every detail is designed to support a thriving business environment.
Its strategic location—just steps from the Montgomery Street BART and MUNI stations—ensures that your commute is as smooth as the building’s storied past. Whether you’re grabbing a coffee at a nearby café like Blue Bottle or enjoying a quick bite at the on-site restaurant, modern-day conveniences await you at this iconic landmark.
Explore Beyond The Mills Building with CityDays
After checking out The Mills Building, why not extend your adventure in San Francisco with a CityDays scavenger or treasure hunt tour?
Scavenger Hunt tours are a great way to bring family and friends—or even dates and colleagues—together for an afternoon of great fun and adventure, solving clues and snapping photos. Clues will lead you to the big sights and those that you'd walk straight past.
For more information about our San Francisco Scavenger Hunts then click here: Top 6 Immersive San Francisco Scavenger Hunts & Treasure Hunts | CityDays.
