A slopper is a chili-smothered hamburger or cheeseburger on a grilled bread. Fries, avocados, and onions are occasionally added. Slopper was developed in the 1950s or 1970s at Gray's Coors Tavern or the Star Bar in Pueblo, Colorado.
Pastrami burgers are served on toasted sesame seed buns with beef patties, pastrami, cheese, tomatoes, shredded lettuce, onions, and fry sauce (ketchup, mayonnaise, sweet relish, and onion powder).
Ramen burgers have a beef patty between two fried ramen noodle buns. Arugula and scallions top the shoyu-sauced beef patty. Ramen blogger Keizo Shimamoto devised the dish in 2013.
Montana's elk burger is a twist on America's famed beef patty-in-a-bun cuisine. Montana is noted for its game meat, especially elk, and elk burgers with delicate, dark-red flesh are a favorite local delicacy.
Wisconsin's sloppy butter burger. Some consider butter burger genuine when ground beef is mixed with butter. Others prefer buttered, toasted, and butter-topped buns.
Chili burgers are hamburgers with a bun, beef patty, and chili con carne on top or on the side. Some locations serve the hamburger open-faced with cheese, onions, and fries.
Oklahoma onion burgers are made by pounding thin onions into beef patties. The onions caramelize and the meat cooks together. American cheese, pickles, mustard or mayonnaise, and soft burger buns complete the burger.
Bison burgers, an American specialty, use bison meat. Bison meat is mistakenly labeled buffalo meat, which is really from African buffaloes and water buffaloes.