TASK DEFINITION: In this task, you're given passages that contain mentions of names of people, places, or things. Some of these mentions refer to the same person, place, or thing. Your job is to write questions that evaluate one's understanding of such references. Good questions are expected to link pronouns (she, her, him, his, their, etc.) or other mentions to people, places, or things to which they may refer. Do not ask questions that can be answered correctly without understanding the paragraph or having multiple answers. Avoid questions that do not link phrases referring to the same entity. For each of your questions, the answer should be one or more phrases in the paragraph, and it should be unambiguous.
PROBLEM: Passage: The Hudson Valley Rail Trail is a paved 4-mile (6.4 km) east–west rail trail in the town of Lloyd in Ulster County, New York, stretching from the Hudson River through the hamlet of Highland. The trail was originally part of the Poughkeepsie Bridge Route, a rail corridor that crossed the Hudson via the Poughkeepsie Bridge. Controlled by a variety of railroads throughout the 19th and 20th centuries, the bridge was damaged and became unusable after a 1974 fire. By the 1980s the corridor's then-owner, Conrail, had routed all rail traffic in the region north through Selkirk, and was eager to relieve itself of the bridge and adjoining rights-of-way. In 1984, it sold the entire property for one dollar to a felon who did not maintain it or pay taxes on it. The section of the corridor west of the Hudson was seized by Ulster County in 1991 and transferred to the town of Lloyd.
During the 1990s, a broadband utility seeking to lay fiber optic cable paid the town to pass through the former corridor. The town used part of its payment to pave the route and open it as a public rail trail in 1997. The creation of the trail was supported by a local Rotary club, which built a pavilion along the trail. The pavilion includes a donated antique caboose. While the trail originally ended at Route 44–55, it was extended eastward between 2009 and 2010, intersecting Route 9W and continuing to the Poughkeepsie Bridge. The extension was paid for by stimulus funding.
The bridge, now a pedestrian walkway called Walkway Over the Hudson, connects the trail with the Dutchess Rail Trail to the east, creating a 30-mile (48 km) rail trail system that spans the Hudson. The trail is expected to be extended west, where it will border Route 299. As it passes through Highland, the trail is carried by several bridges, connects to four parking areas, and traverses a wetlands complex. The trail forms part of the proposed Empire State Trail.

SOLUTION: What is the full name of the structure that was damaged and became unusable after a fire in 1974?

PROBLEM: Passage: The Willamette River ( (listen) wil-AM-it) is a major tributary of the Columbia River, accounting for 12 to 15 percent of the Columbia's flow. The Willamette's main stem is 187 miles (301 km) long, lying entirely in northwestern Oregon in the United States. Flowing northward between the Oregon Coast Range and the Cascade Range, the river and its tributaries form the Willamette Valley, a basin that contains two-thirds of Oregon's population, including the state capital, Salem, and the state's largest city, Portland, which surrounds the Willamette's mouth at the Columbia.
Originally created by plate tectonics about 35 million years ago and subsequently altered by volcanism and erosion, the river's drainage basin was significantly modified by the Missoula Floods at the end of the most recent ice age. Humans began living in the watershed over 10,000 years ago. There were once many tribal villages along the lower river and in the area around its mouth on the Columbia. Indigenous peoples lived throughout the upper reaches of the basin as well.
Rich with sediments deposited by flooding and fed by prolific rainfall on the western side of the Cascades, the Willamette Valley is one of the most fertile agricultural regions in North America, and was thus the destination of many 19th-century pioneers traveling west along the Oregon Trail. The river was an important transportation route in the 19th century, although Willamette Falls, just upstream from Portland, was a major barrier to boat traffic. In the 21st century, major highways follow the river, and roads cross it on more than 50 bridges.
Since 1900, more than 15 large dams and many smaller ones have been built in the Willamette's drainage basin, 13 of which are operated by the U.S. Army Corps of Engineers (USACE). The dams are used primarily to produce hydroelectricity, to maintain reservoirs for recreation, and to prevent flooding. The river and its tributaries support 60 fish species, including many species of salmon and trout; this is despite the dams, other alterations, and pollution (especially on the river's lower reaches). Part of the Willamette Floodplain was established as a National Natural Landmark in 1987 and the river was named as one of 14 American Heritage Rivers in 1998.

SOLUTION: What organization operates 13 of the dams built in the river that is a major tributary of the Columbia river?

PROBLEM: Passage: According to academic Rob Wilson, San Francisco is a global city, a status that pre-dated the city's popularity during the California Gold Rush. Such cities are characterized by their ethnic clustering, network of international connectivity, and convergence of technological innovation. Global cities, such as San Francisco, are considered to be complex and require a high level of talent as well as large masses of low wage workers. A divide is created within the city of ethnic, typically lower-class neighborhoods, and expensive ones with newly developed buildings. This in turn creates a population of highly educated, white-collar individuals as well as blue-collar workers, many of whom are immigrants, and who both are drawn to the increasing number of opportunities available. Competition for these opportunities pushes growth and adaptation in world centers.San Francisco has a diversified service economy, with employment spread across a wide range of professional services, including financial services, tourism, and (increasingly) high technology. In 2016, approximately 27% of workers were employed in professional business services; 14% in leisure and hospitality; 13% in government services; 12% in education and health care; 11% in trade, transportation, and utilities; and 8% in financial activities. In 2017, GDP in the five-county San Francisco metropolitan area grew 3.4% to $501 billion. Additionally, in 2017 the 14-county San Jose–San Francisco–Oakland combined statistical area had a GDP of $907 billion, ranking 3rd among CSAs, and ahead of all but 16 countries. As of 2017, San Francisco County was the 7th highest-income county in the United States (among 3,142), with a per capita personal income of $119,868. Marin County, directly to the north over the Golden Gate Bridge, and San Mateo County, directly to the south on the Peninsula, were the 5th and 9th highest-income counties respectively.

SOLUTION:
What county has the 5th highest-income county in the United States?