Glacier National Park is an American national park located in northwestern Montana, on the CanadaUnited States border, adjacent to the Canadian provinces of Alberta and British Columbia. The park encompasses more than 1 million acres (4,000 km2) and includes parts of two mountain ranges (sub-ranges of the Rocky Mountains), more than 130 named lakes, more than 1,000 different species of plants, and hundreds of species of animals. This vast pristine ecosystem is the centerpiece of what has been referred to as the "Crown of the Continent Ecosystem," a region of protected land encompassing 16,000 square miles (41,000 km2).The region that became Glacier National Park was first inhabited by Native Americans. Upon the arrival of European explorers, it was dominated by the Blackfeet in the east and the Flathead in the western regions. Under pressure, the Blackfeet ceded the mountainous parts of their treaty lands in 1895 to the federal government; it later became part of the park. Soon after the establishment of the park on May 11, 1910, a number of hotels and chalets were constructed by the Great Northern Railway. These historic hotels and chalets are listed as National Historic Landmarks and a total of 350 locations are on the National Register of Historic Places. By 1932 work was completed on the Going-to-the-Sun Road, later designated a National Historic Civil Engineering Landmark, which provided greater accessibility for automobiles into the heart of the park.

Glacier National Park's mountains began forming 170 million years ago when ancient rocks were forced eastward up and over much younger rock strata. Known as the Lewis Overthrust, these sedimentary rocks are considered to have some of the finest examples of early life fossils on Earth. The current shapes of the Lewis and Livingston mountain ranges and positioning and size of the lakes show the telltale evidence of massive glacial action, which carved U-shaped valleys and left behind moraines that impounded water, creating lakes. Of the estimated 150 glaciers which existed in the park in the mid-19th century during the late Little Ice Age, only 25 active glaciers remained by 2010. Scientists studying the glaciers in the park have estimated that all the active glaciers may disappear by 2030 if current climate patterns persist.Glacier National Park has almost all its original native plant and animal species. Large mammals such as grizzly bears, moose, and mountain goats, as well as rare or endangered species like wolverines and Canadian lynxes, inhabit the park. Hundreds of species of birds, more than a dozen fish species, and a few reptiles and amphibian species have been documented. The park has numerous ecosystems ranging from prairie to tundra. The easternmost forests of western redcedar and hemlock grow in the southwest portion of the park. Forest fires are common in the park. There has been a fire every year of the park's existence except 1964. 64 fires occurred in 1936, the most on record. In 2003, six fires burned approximately 136,000 acres (550 km2), more than 13% of the park.Glacier National Park borders Waterton Lakes National Park in Canadathe two parks are known as the Waterton-Glacier International Peace Park and were designated as the world's first International Peace Park in 1932. Both parks were designated by the United Nations as Biosphere Reserves in 1976, and in 1995 as World Heritage Sites. In April 2017, the joint park received a provisional Gold Tier designation as Waterton-Glacier International Dark Sky Park through the International Dark Sky Association, the first transboundary dark sky park.

The United States Congress is the legislature of the federal government of the United States. It is bicameral, being composed of a lower body, the House of Representatives, and an upper body, the Senate. The Congress meets in the United States Capitol in Washington, D.C. Both senators and representatives are chosen through direct election, though vacancies in the Senate may be filled by a governor's appointment. Congress has 535 voting members: 100 senators and 435 representatives. The vice president of the United States has a vote in the Senate only when senators are evenly divided. The House of Representatives has six non-voting members.The sitting of a Congress is for a two-year term, at present, beginning every other January. Elections are held every even-numbered year on Election Day. The members of the House of Representatives are elected for the two-year term of a Congress. The Reapportionment Act of 1929 establishes that they be elected in single-member constituencies or districts by first-past-the-post and that Congressional districts be apportioned to states by population every ten years using the United States Census results, provided that each state has at least one Congressional representative. Each senator is elected at-large in their state for a six-year term, with terms staggered, so every two years approximately one-third of the Senate is up for election. Each state, regardless of population or size, has two senators, so currently, there are 100 senators for the 50 states.

Article One of the United States Constitution requires that members of Congress must be at least 25 years old (House) or at least 30 years old (Senate), have been a citizen of the United States for seven (House) or nine (Senate) years, and be an inhabitant of the state which they represent. Members in both chambers may stand for re-election an unlimited number of times.

The Congress was created by the Constitution of the United States and first met in 1789, replacing in its legislative function the Congress of the Confederation. Although not legally mandated, in practice since the 19th century, Congress members are typically affiliated with one of the two major parties, the Democratic Party or the Republican Party, and only rarely with a third party or independents affiliated with no party. In the case of the latter, the lack of affiliation with a political party does not mean that such members are unable to caucus with members of the political parties. Members can also switch parties at any time, although this is quite uncommon.