The Cody people were camping on these shores around 7300 BC, fishing and boating on the lake, hunting bear and bison, and making the journey to Obsidian Cliff for the volcanic glass they needed for tools. Various Native cultures followed, hunting bighorn sheep, fishing for cutthroat trout, and gathering bitterroot and camas bulbs. The only Native American pottery ever found within present-day Yellowstone National Park came from the western shore near Pumice Point, dating between 500 and 1500 AD and linked to the Shoshone people. John Colter became the first person of European descent to see the lake in the early 1800s. By 1836, trapper Osborne Russell was describing the hot springs that 'boiled perpetually' and steam vents that could be heard five or six miles distant.

This water fills part of the Yellowstone Caldera, the scar left when the magma chamber collapsed 640,000 years ago in a cataclysmic eruption. The original lake once stood higher, extending north across what is now Hayden Valley to the base of Mount Washburn. Scientists discovered in the 1990s that two volcanic vents called resurgent domes are still rising, averaging about one inch of uplift per year. The Sour Creek Dome, just north of Fishing Bridge, is causing the entire lake to tilt southward. Today you can find larger sandy beaches appearing on the north shore while the southern arms slowly flood. Beneath the surface, a mysterious bulge stretches along the lake floor, marked by faults, hot springs, and small craters. The West Thumb Geyser Basin offers visitors a front-row seat to this geological drama, where geysers and fumaroles steam both alongside and directly within the lake.

On July 28, 1871, the Hayden Geological Survey launched the Annie, just 4.5 feet wide and 11 feet long, the first European boat ever to sail these waters. Dr. Ferdinand Hayden and his 34-man team spent fifteen days charting the remote southern and eastern shores, using a system of compass bearings to map soundings. They landed on islands they believed no human had ever touched, naming one Stevenson's Island after the man who first set foot upon it. William Henry Jackson accompanied the expedition, capturing the first photographs of the lake. The Hayden party also brought the first wheeled vehicle to these shores, an odometer cart to measure distances. Their scientific documentation helped convince Congress to create Yellowstone National Park the following year.

When early explorers waded into the shallows with grasshopper bait, cutthroat trout were so abundant that two men could catch them faster than six could clean them. In 1994, non-native lake trout were discovered in Yellowstone Lake, believed to have been introduced from nearby Lewis Lake as early as 1989. The invaders triggered an ecological crisis. Lake trout hunt cutthroat trout aggressively, and unlike cutthroat, they spawn in deep water where grizzly bears, river otters, and osprey cannot reach them. The National Park Service now runs an aggressive eradication program, requiring all lake trout caught by anglers to be killed while native cutthroat must be released. The longnose sucker, another invasive species introduced in the late 1980s or early 1990s, compounds the pressure by competing for the same food sources.

By early December, ice nearly thick enough to walk on seals much of the lake, remaining frozen until late May or early June. But look carefully and you will find patches of open water where shallow depths cover hot springs, windows where the volcanic heat below refuses to let winter fully claim its territory. The lake drains north through its only outlet at Fishing Bridge, though scientists believe it originally flowed south to the Pacific via the Snake River. Just downstream, the Yellowstone River plunges over the Upper and Lower Falls before racing through the Grand Canyon of the Yellowstone. Today, a marina at Bridge Bay offers boat rentals, and backcountry campsites accessible only by water line the southern shores. The Nine Mile Post trail follows the eastern shoreline into the remote Thorofare region, one of the most isolated places in the lower 48 states.