On July 1, 1891, Pourtales opened The Broadmoor Casino, and a small hotel followed a few years later. Part of his plan was to subdivide the land around the casino as home sites. To make the home sites even more attractive, he created a lake to serve as a focal point. However, once complete, the lake quickly drained dry. The cause: the lake sat above an extensive prairie dog tunnel system. At a high price the tunnels and the bottom of the lake were sealed with clay. Never short on dreams but increasingly short on cash, Pourtales had finally reached his financial limit.

Though the property seemed destined to slip into slumber, it still had one more dreamer to go, and he was the biggest of them all. Spencer Penrose of Philadelphia brought his money from gold and copper mining and his wife, Julie, to the Pikes Peak region. Having won in the mining industry, Penrose turned his sights on becoming a hotelier. He conceived a hotel of grandeur on a scale this country had never seen and Penrose had the money to make the dream come true.

On May 9, 1916, Penrose bought the Broadmoor Casino and Hotel and its 40 acres along with 400 additional acres. He incorporated it into the Broadmoor Hotel and Land Company. Due to the unusual spelling of the hotel's name, he was able to trademark the word Historians speculate that the raised might have been an insult to the Antlers, a hotel for which Penrose had a great deal of animosity after he was turned away for riding his horse into the bar, and after his friend was fired as hotel manager. Both incidents are also seen as the possible reasons Penrose went into the business at all.

The New York architectural and design firm of Warren and Wetmore was hired to build the Broadmoor in Italian Renaissance style with four wings and a curved marble staircase. It was completed in June 1918 and held a grand opening on the 29th of the month. Playing to the American pastime of golf, Penrose built an 18-hole course by master golf-course designer Donald Ross.