Steamboat Geyser, in Yellowstone National Park's Norris Geyser Basin, is the world's tallest currently-active geyser. Steamboat Geyser has two vents, a northern and a southern, approximately apart. The north vent is responsible for the tallest water columns; the south vent's water columns are shorter. Prior to 1904, Waimangu Geyser, in New Zealand, had some taller eruptions capable of reaching , but in 1904, a landslide changed the local water table, and since then, Waimangu has not erupted. Excelsior Geyser in Yellowstone's Midway Geyser Basin, and Semi-Centennial Geyser just north of Roaring Mountain on the Grand Loop Road were reported to be as tall as Steamboat, both with eruptions reaching . However, Excelsior has not erupted since 1985, and now functions as a hot spring, and Semi-Centennial's one eruption of this height was reported in 1922 and it has been dormant since. Steamboat's major eruptions generally last from 3 to 40 minutes (several durations surpassing an hour were observed during the 2018 active phase), and are followed by powerful jets of steam. During these eruptions, water may be thrown more than into the air. Steamboat does not erupt on a predictable schedule, with recorded intervals between major eruptions ranging from three days to fifty years. The geyser was dormant from 1911 to 1961. In 1964, twenty-nine eruptions were reported, setting the record for the most eruptions within a calendar year. In 2018, the geyser began a prolonged period of frequent activity lasting through at least 2022, with more than 40 eruptions recorded annually in both 2019 and 2020. Minor eruptions of are much more frequent. After an eruption, the geyser often vents large amounts of steam for up to 48 hours. Sometimes during this part of an eruption, water may return to Steamboat, causing it to jet water once again, though to lesser heights. Cistern Spring, located nearby, will drain completely following a major eruption of the geyser; the spring refills within a few days. Recent eruptions and active phase of 2018–2023 The most recent eruption of Steamboat Geyser occurred on January 28, 2023. This was the 161st eruption since it re-activated in early 2018. In 2019 the 48th eruption occurred on December 26th. That set a new record for the most eruptions within a calendar year. The calendar year 2020 also saw 48 eruptions, tying the record set in 2019. Eruptions from 1990 to 2017 June 4, 1990 October 2,