Question: William Gladstone Steel is the father of which caldera lake in south-central Oregon in the western United States?

Context paragraphs:
Paisley Caves: The Paisley Caves complex is a system of four caves in an arid, desolate region of south-central Oregon, United States north of the present-day city of Paisley, Oregon.  The caves are located in the Summer Lake basin at 4520 ft elevation and face to the west in a ridge of Miocene and Pliocene era basalts mixed with soft volcanic tuffs and breccias, from which the caves were carved by Pleistocene-era waves from Summer Lake.  One of the caves may contain archaeological evidence of the oldest definitively-dated human presence in North America.  The site was first studied by Luther Cressman in the 1930s.

Goose Lake Valley: The Goose Lake Valley is located in south-central Oregon and northeastern California in the United States.  It is a high valley at the northwestern corner of North America's Great Basin.  Much of the valley floor is covered by Goose Lake, a large endorheic lake that straddles the Oregon–California border.  Native Americans inhabited the Goose Lake Valley for thousands of years before explorers arrived in the 19th century.  The pioneer wagon route known as the Applegate Trail crossed the Goose Lake Valley on its way to southern Oregon.  At the south end of Goose Lake, the Lassen Cutoff separated from the Applegate Trail and headed south toward the Sacramento Valley.  Today, Lakeview, Oregon, is the largest settlement in the valley.  Livestock ranching and lumber mills are the valley's main commercial activity.  The Goose Lake Valley offers a number of recreational opportunities including hang-gliding, hunting, fishing, and birdwatching.

Crater Lake: Crater Lake (Klamath: giiwas) is a caldera lake in south-central Oregon in the western United States.  It is the main feature of Crater Lake National Park and is famous for its deep blue color and water clarity.  The lake partly fills a nearly 2148 ft -deep caldera that was formed around 7,700 (± 150) years ago

William Gladstone Steel: William Gladstone Steel (September 7, 1854 – October 21, 1934), called the "father of Crater Lake", referring to the creation of Crater Lake National Park in Oregon, United States.  A native of Ohio, he worked in the newspaper business before becoming a mail carrier.  He campaigned Congress for 17 years to designate Crater Lake as a national park.

Hager Mountain: Hager Mountain is a volcanic peak in Oregon in the northwest corner of the Basin and Range Province in the United States.  The mountain is located south of the small unincorporated community of Silver Lake in south-central Oregon, and it is in the Fremont–Winema National Forest.  On the summit, there is a fire lookout operated during the summer and fall by the United States Forest Service.  There are several hiking trails that lead to the lookout station.

Wizard Island: Wizard Island is a volcanic cinder cone which forms an island at the west end of Crater Lake in Crater Lake National Park, Oregon.  The top of the island reaches 6933 ft above sea level, about 755 ft above the average surface of the lake.  The cone is capped by a volcanic crater about 500 ft wide and 100 ft deep.  The crater was named the "Witches Cauldron" by William Gladstone Steel in 1885, who also gave Wizard Island its name at the same time.

Williamson River (Oregon): The Williamson River of south-central Oregon in the United States is about 100 mi long.  It drains about 3000 mi2 east of the Cascade Range.  Together with its principal tributary, the Sprague River, it provides over half the inflow to Upper Klamath Lake, the largest freshwater lake in Oregon.  The lake's outlet is the Link River, which flows into Lake Ewauna and the Klamath River.

Camp Warner: Camp Warner was a United States Army outpost in south-central Oregon, United States.  Camp Warner was located at two different sites approximately 35 mi apart.  The Army called both sites Camp Warner.  However, the first site became known as Old Camp Warner.  It was used as winter quarters in 1866–1867 and then abandoned.  The second, more developed site is generally known as Fort Warner (or New Camp Warner), although the Army never officially designated it as a fort.  Fort Warner was used as a supply depot and administrative headquarters from 1867 to 1874 during a protracted Army campaign against Northern Paiute bands in Eastern Oregon and Northern California.  Today, nothing remains of either Old Camp Warner or Fort Warner.

Upper Klamath Lake: Upper Klamath Lake (sometimes called Klamath Lake) (Klamath: ? ews, "lake" ) is a large, shallow freshwater lake east of the Cascade Range in south-central Oregon in the United States.  The largest body of fresh water by surface area in Oregon, it is approximately 25 mi long and 8 mi wide and extends northwest from the city of Klamath Falls.  It sits at an average elevation of 4140 ft .

Crane Mountain: Crane Mountain is in the Warner Mountain range and is the tallest peak in Lake County, Oregon, U.S..  It is located southeast of Lakeview in south-central Oregon, near the northwest corner of the Basin and Range Province of the western United States.  The mountain is in the Fremont section of the Fremont–Winema National Forest.  There was a United States Forest Service fire lookout located near the summit which was removed in 1972.  The Crane Mountain National Recreation Trail runs north and south along the crest of the mountain.

Supporting paragraphs: William Gladstone Steel Crater Lake
Answer: Crater Lake