Ancon Rock is a reef located about 0.5 miles (0.8 km) off Point Gustavus on the eastern shore, at the entrance to Glacier Bay, within Glacier Bay National Park and Preserve. It lies approximately 55 miles (89 km) west of Juneau and 8.5 miles (12 km) southwest of Gustavus, Alaska. The rock was named after the sidewheel steamship Ancon, which ran aground here in 1886. The reef is a submerged extension of a glacial moraine that formed Point Gustavus during the Little Ice Age of the Neoglacial period between 5,500 and 200 years ago. In the centuries before the maximum glacial advance, a glacier filling present-day Glacier Bay had formed a stationary front at the head of Bartlett Cove and built an outwash plain southward to the mouth of Glacier Bay. In 1794, Lieutenant Joseph Whidbey of the Vancouver Expedition mapped the terminus of the Glacier Bay icefield, which had already begun retreating from the terminal moraine but still extended well out into Icy Strait. Today, the terminal moraine is mostly submerged in Icy Strait but merges with the lateral moraine at Point Gustavus. Post-glacial rebound is causing a gradual uplifting of the submerged bottom, which has elevated the submerged moraine to form reefs. Today, vessels are advised to stay well offshore when rounding Point Gustavus. Ancon Rock is a notorious navigational hazard, uncovering 1 foot (0.3 m) at low tide, about 0.4 miles (0.6 km) south-southwest of Point Gustavus. Another rock uncovers 3 feet (1 m) at low tide, about 0.2 miles (0.3 km) northwest of Ancon Rock.

 In 1867, the Alaska Purchase transferred the territory from Russia to the United States, and a mild post-Civil War rush of miners, fishermen, and prospective settlers arrived to seek opportunities in the newly acquired territory. By 1873, efforts to establish a municipal government at Sitka had collapsed, and many optimistic pioneers returned to the ‘lower 48.’ In 1877, occupation units of the U.S. Army, after ten years of idleness, gladly abandoned the territory. In 1879, a band of Tlingits threatened Sitka, and the British man-of-war HMS Osprey had to be called in to save the lawless town. During the early 1880s, Alaska’s appeal to fortune seekers enjoyed a resurgence when gold was discovered at Juneau. Around the same time, salmon canneries and herring salteries were proliferating. The number of vessels traveling the Inside Passage multiplied accordingly. Companies like the Pacific Coast Steamship found profit in transporting gold, fish, lumber, and mining equipment, but they also sought paying passengers to fill empty berths. In 1879, John Muir first visited Alaska, and the articles he wrote described the attractions of an Inside Passage vacation. A few years later, Captain James C. Car­roll delighted passengers aboard his steamer SS Idaho with the fairyland sights of Glacier Bay. In 1883, Eliza Scidmore, from Iowa, wanted to see more of the world and purchased a ticket to Alaska on the Idaho. She wrote newspaper and magazine articles about her travels and, in 1885, published the first Alaska travel guide. While in Glacier Bay, Scidmore described meeting Tlingit families who were hunting in the bay for the summer, interacting with pioneers like Dick Willoughby, and recounting the efforts Captain Carroll took to get the Idaho to the face of a tidewater glacier. These publications, and others, influenced the opening of Alaska to western tourism.

SS Ancon was launched in 1867 as a double-ended ferry for service in Panama for the Pacific Mail Steamship Company. In 1872, the hull was rebuilt, a larger engine of 400 horsepower was installed, and the capacity was significantly increased for transporting passengers and cargo. In this configuration, Ancon sailed between San Francisco and San Diego from 1875 to 1887, and in 1878, Ancon also made periodic trips between San Francisco and Portland. Cruising to Alaska became popular in the 1880s, so the Pacific Coast Steamship Company used Ancon for summer excursion cruises sailing the Inside Passage between Puget Sound and Alaska. At 9:57 p.m. on September 13, 1886, Ancon was under the command of Captain Carroll and cruising past Point Gustavus in Icy Strait, heading into Glacier Bay. Most of the 14 passengers were asleep in their staterooms when the ship made the turn into Glacier Bay and grounded hard on an uncharted rock. Three hours later, the tide had risen sufficiently for Ancon to float free, but water in the hold had extinguished the boiler fires, and both the pumps and engines were disabled. The sails were raised, and Carroll beached the ship on a sandy shore in Bartlett Cove. There was no radio in 1886, so Carroll sent the ship’s launch to Sitka on the morning of September 14 to seek help. The USS Pinta arrived on September 19 from Sitka, bringing carpenters and planking for repairs. On September 26, Idaho arrived, and the passengers were transferred. No other ship carried news of the wreck to the world until Idaho reached Victoria, British Columbia, with Ancon‘s passengers on October 8. The U.S. Coast and Geodetic Survey was immediately sent to chart the rock, which they named Ancon Rock. Ancon was repaired and returned to service, and three years later, on August 28, 1889, after departing from Loring, Alaska, with cases of processed salmon, Ancon ran onto a submerged and uncharted reef in the harbor and sank. Read more here and here. Explore more of Ancon Rock and Point Gustavus here: