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.
One example: Passage: Nearing London, Oliver encounters Jack Dawkins, a pickpocket more commonly known by the nickname the "Artful Dodger", and his sidekick, a boy of a humorous nature named Charley Bates, but Oliver's innocent and trusting nature fails to see any dishonesty in their actions. The Dodger provides Oliver with a free meal and tells him of a gentleman in London who will "give him lodgings for nothing, and never ask for change". Grateful for the unexpected assistance, Oliver follows the Dodger to the "old gentleman's" residence. In this way Oliver unwittingly falls in with an infamous Jewish criminal known as Fagin, the gentleman of whom the Artful Dodger spoke. Ensnared, Oliver lives with Fagin and his gang of juvenile pickpockets in their lair at Saffron Hill for some time, unaware of their criminal occupations. He believes they make wallets and handkerchiefs.
Solution is here: Who believes Fagin's gang make wallets and handkerchiefs?.
Explanation: This question is based on the following sentence in the passage "He believes they make wallets and handkerchiefs". It evaluates the understanding that the pronoun "he" refers to name "Oliver". You can ask questions like this one about most pronouns in a paragraph.

Now, solve this: Passage: The West Plains Trail had originated with Native Americans, and before the ox cart traffic it connected the fur-trading posts of the Columbia Fur Company.  In fact, that company introduced the Red River ox cart to haul its furs and goods. It also developed the trails, and by the early 1830s, an expedition from the Selkirk settlement driving a flock of sheep from Kentucky to the Assiniboine found the trail to be well-marked.From the Red River Settlement, the trail went south upstream along the Red River's west bank to Pembina, just across the international border. Pembina had been a fur-trading post since the last decade of the eighteenth century.  From there, some traffic continued south along the river, but most cart trains went west along the Pembina River to St. Joseph near the border and then south, or else cut the corner to the southwest in order to intercept the southbound trail from St. Joseph. This north-south trail paralleled the Red River about thirty miles (50 km) to the west.  By staying on the uplands west of the Red River, this route avoided crossing the tributaries of that river near their confluences with the Red, and also kept out of the swampy, flood-prone, and mosquito-ridden bottomlands in the lakebed of Glacial Lake Agassiz which the river drained.
In what is now southeastern North Dakota, the trail veered to the south-southeast to close with the Red River at Georgetown, Fort Abercrombie, and Breckenridge, Minnesota, all of which came into existence in consequence of the passing cart traffic.  From Breckenridge, the trail continued upstream along the east bank of the Red and Bois des Sioux Rivers to the continental divide at Lake Traverse. Some traffic went along the lakeshore through the Traverse Gap on the continental divide, then down either side of Big Stone Lake, source of the Minnesota River, while other carters took a short cut directly south from the Bois des Sioux across the open prairie through modern Graceville, Minnesota thereby avoiding the wet country in the Traverse Gap.The trail continued on intertwined routes down both sides of the valley of the Minnesota River past fur posts at Lac qui Parle and downstream locations, and the Upper Sioux and Lower Sioux Indian Agencies and Fort Ridgely, all established in the 1850s. From Fort Ridgely, the trail struck across the open prairie to the Minnesota River at Traverse des Sioux near modern-day St. Peter, Minnesota, where the furs and goods were, at first, usually transshipped to flatboats.  In later years, most cart trains crossed to the east bank and proceeded northeast along the wooded river bottoms and uplands to Fort Snelling or Mendota, where the Minnesota River joined the Mississippi.  From there furs were shipped down the Mississippi River to Saint Louis and other markets.
Solution:
Before shipping goods down the Mississippi river. what river did most cart trains follow?