Editing Keystone Resort (section)

===1990s===
In 1990, Keystone entered the detachable industry as [[Doppelmayr USA|Doppelmayr]] constructed two [[Detachable chairlift|high speed quads]] to replace aging lifts on Dercum Mountain. The Peru Express lift replaced a Heron Poma double, providing access from the Mountain House base area to the Packsaddle Bowl and the west side of the mountain. It was supplemented by the Montezuma Express lift, which replaced a Yan triple chairlift and provided access to all trails on the upper and central part of Dercum Mountain.

In 1991, Keystone opened an expansion into the Outback, located beyond North Peak. Doppelmayr constructed three new lifts to service the expansion. A two-way gondola, known as the Outpost Gondola, was built from the summit of Dercum Mountain over to North Peak. A new high speed quad known as the Outback Express was built to service the Outback trails, and a fixed-grip quad known as the Wayback was built to service two access trails leading to the Outback as well as provide egress from the area.

In 1996, [[Vail Resorts]] announced plans to acquire Keystone and Breckenridge's parent company Ralston Resorts Inc. from Ralston Purina. The merger was approved by the [[U.S. Department of Justice]] on January 3, 1997.<ref>{{Cite web|url=https://www.justice.gov/archive/atr/public/press_releases/1997/1021.htm|title = Colorado Ski Resort Merger Approved with Conditions to Keep Prices Lower for Skiers}}</ref>

In 1997, the Erickson triple chairlift on Dercum Mountain was removed and replaced with a new Doppelmayr high speed quad, named the Summit Express, running parallel to the River Run Gondola for its entire length. That same year, a new triple chairlift known as the Ranger was built to open up a learning area at the summit of Dercum Mountain.

In 1998, the Santiago Express was built to replace the Santiago triple chairlift on North Peak.