LOOK in your atlas for Michigan. Then let your eyes wander to the top of the page, or as far north as you can go, looking for the UP - that is, the Upper Peninsula of Michigan. Most likely the UP will not be on the same page as the Lower Peninsula of Michigan. Many people have never heard of the Upper Peninsula and don't realize there's more to Michigan north of the Mackinac Bridge, which has spanned the Straits of Mackinac connecting the two peninsulas since 1957.Walter North has worked at the Mackinac Bridge for the past 26 years and says it's still common for people to come to "the bridge" and, not realizing they are still in Michigan, ask questions like: Are we in Canada now? Do you take US money? How much can we take in with us? How much can we take out? Do you need to see a passport? From 1835 to 1837, Michigan and Ohio militias engaged in border skirmishes. The states agreed in 1837 that Toledo belonged to Ohio; Michigan got the UP as a consolation prize. Quite a consolation. This 315-mile-long peninsula is surrounded by three of the Great Lakes - Superior to the north, Michigan to the south, and Huron to the southeast. It meets with Canada at the St. Mary's River on the east, and borders Wisconsin on the west. Fred Rydholm, an Upper Peninsula historian, says: "The UP has the most beautiful summers in the world. It has more woods than anywhere; even Marquette county, which is the largest and most populated county in the Upper Peninsula, is 95 percent forested. We have Lake Superior, and many beautiful inland lakes and rivers. It hasn't really been discovered as a tourist area because it isn't as commercialized as other places." The role of the lakes in the UP's settlement and development is obvious - from the earliest encampments along the bays of the lakes to the development of shipping channels for transporting the bountiful natural resources of copper, iron, and timber from the UP to the Lower Peninsula, Chicago, and Canada. Dr. Douglass Houghton, Michigan's first state geologist, led an exploratory mission through the UP and published a mineral report in 1840 that led to extensive mining and timber cutting. Miners, loggers, and laborers immigrated from England, Germany, Finland, Ireland, and Canada to exploit these resources. "The people that came here were pioneers in all fields - logging, mining, fishing, banking, and medicine," says Mr. Rydholm. "These people had strong character - they were climbers. They had to be inventive. They were honest, hard-working, faithful, and very reliable." The extraction of copper, iron, and timber kept the UP economy booming for decades. But with the depletion of these resources, the economy is changing for the first time in over 100 years, says H. Richard Anderson, director of the Northern Economic Initiatives Center (NEIC), a business development program affiliated with Northern Michigan University (NMU). In 1982, unemployment in the UP hit a high of 18.2 percent. The June 1991 unemployment rate was 10.2 percent says Kathy Salow, Labor Market Analyst for the Michigan Employment Security Commission in Marquette, Mich. When NEIC analysts looked at the Upper Peninsula's business trends for the period from 1982 to 1988, they discovered that about 2,500 new firms had formed with an average of two-to-three employees each. Most of these businesses prospered and steadily grew to employ an average of seven workers. These new businesses are mainly retail and services, catering to the tourism industry. Mr. Anderson says his staff is directing its "attention to assisting in restructuring this resource-based economy. It's not gro wth we're after, but stability." A 1989 summer tourism survey conducted by Anderson's staff showed that tourism grew faster in the Upper Peninsula than nationwide, and most of the tourists surveyed indicated they were attracted by the UP's natural beauty - the shorelines, waterfalls, parks, museums, and historical landmarks. John VandeZande, a NMU professor and fiction writer who sets many of his short stories in the Upper Peninsula, says: "There is an instinct for survival to stay here. The mines tend to dictate our economic health. If you prize the area enough, you will try to stay, which means you will put up with tough conditions. Most people that live here tend to cherish the UP."