I think this timeline from the Michigan Wildlife Conservancy says it all:

MILESTONES IN THE HISTORY OF COUGARS IN MICHIGAN

Pre-Settlement – Cougars are indigenous to all 83 counties of Michigan.

1830 – 1930 – Cougars and other predators are hunted and trapped by the government and citizens to accommodate the expanding human population.

1907 – The Sault St. Marie Evening News reports on a five-foot six-inch, 80-pound male cougar killed in a wolf trap near the Tahquamenon River in Chippewa County.

1914 – 1922 – N.A. Wood of the University of Michigan Museum summarizes historical accounts of cougars in both the Upper and Lower Peninsula. The Michigan Conservation Department begins to list cougars among predators vanished from the state.

1946 – 1960 – Based on cougar sighting reports since the 1930s, naturalists and reporters begin to question whether cougars are actually gone from Michigan. In his 1948 scientific paper on the wildlife of the Huron Mountains in the Upper Peninsula, R.H. Manville reports several sightings of cougars by “reliable people.” Many newspaper articles about sightings of the “mystery cat” appear, especially around Sault Ste. Marie and a few other areas of the Upper Peninsula. Michigan Conservation Department biologists quoted in newspaper articles continue to claim the cougar is extirpated.

1966 – Francis Opolka, then a conservation officer who later became Deputy Director of the Michigan Department of Natural Resources, and another officer observe a cougar near Cornell in Delta County while on patrol. A plaster cast of the animal’s track is made the next day and later verified as that of “a large cat” by University of Michigan zoologists.

1970 – A few citizens, such as Ed Klima of Crystal Falls, begin to record some of the more credible cougar sightings of Upper Peninsula residents.

1977 – David LaPointe, then Assist. Manager of the Porcupine Mountains State Park and a wildlife biologist, writes an account of cougar tracks he found in the Park in “Michigan Natural Resources Magazine,” official publication of the DNR.

1981 – DNR Forester Mike Zuidema, after seeing a cougar in the wild in Michigan, begins compiling detailed records of cougar sightings, primarily in the Central Upper Peninsula.

1984 – Blood-covered bone fragments are recovered from a cougar reportedly shot in Menominee County. Zuidema forwards the sample to Colorado State University where it is determined by high-resolution electrophoresis to have “a positive identity to mountain lion.” This finding is included in an official DNR “Necropsy Record” for the incident.

1985 – 1990 – Various outdoor reporters continue to revisit the question of whether there are wild cougars in Michigan. Most DNR wildlife biologists quoted in articles deny the existence of the cougars. This is a time of controversy.

1987 – The cougar is listed as an endangered species in Michigan by the DNR.

1994 – The status of the cougar in Michigan is reviewed in a book edited by Dr. David C. Evers, “Endangered and Threatened Wildlife of Michigan.” The publication is the result of a long-term project funded by the Nongame Wildlife Fund of the Natural Heritage Program of the DNR and was reviewed by no fewer than six active and retired DNR wildlife officials and many other prominent mammalogists. Its highlights include these statements about cougars: “Today, several areas throughout its former range, including northern Michigan, may support small populations of cougars… There are also encouraging signs that the Michigan cougar is not transient but occurs in
a self-sustaining population – based on several reliable sightings of adult cougars with kittens… The existence of the cougar in Michigan has only been recently confirmed. Whether individuals are
from small, remnant populations that survived human pressures through the last two centuries, transients from the western Great Lakes Region, or privately released (or escaped) western subspecies, the cougar needs to be recognized, protected, and studied in Michigan’s Upper Peninsula.”

1995 – Individual DNR biologists continue to receive information about cougars. Hair from a reported cougar collision with a car in Iron County is found to match that of cougar. However, the biologist who performed the microscopic examination files no report because he assumes the animal must be an escaped or released pet, then discards the hair.

1997 – The Detroit Free Press publishes a very clear photograph of a cougar in Alcona County taken by Jim Deutsch on the property of Larry Lippert. DNR personnel try to discredit the photo and the photographer.

1998 – The Michigan Wildlife Conservancy (MWC) starts to investigate the many sightings and physical evidence of cougars in the Upper Peninsula at the behest of Dan Robbins, a co-founder of the organization.

1998 – Longtime DNR wildlife biologist Lawrence Robinson emails his supervisors in the Lansing Headquarters to report his cougar sighting in Alcona County. His report started, “This is a note I absolutely dread writing. I don’t know if Glen talked to you yet, but I had the terrible misfortune of seeing the Alcona County cougar… I figured I had to fess up eventually. What do I do to get the pictures and info to our division files without this getting out to the media?” Robinson ended by saying, “ By the way, the location is about 10 miles “as the cougar flies” from the Lippert property where the picture was taken last summer.”

1998 – Photographs of a cougar taken by James McCarthy in Schoolcraft County near Seul Choix Point receive widespread coverage from television and print media.

2001 – The MWC publishes a technical report summarizing cougar sightings, physical evidence, and related information. It concludes Michigan has a small, and likely remnant, population of cougars.

2001 – 2002 – The MWC begins to release information from field studies launched in May of 2001. The Conservancy’s field crew finds physical evidence, including tracks, cougar-killed deer, and droppings (verified as cougar by DNA analysis) at multiple sites in both the Upper and Lower Peninsulas. Two cougars are actually seen in Roscommon and Benzie Counties during the fieldwork. A cougar skull is found by a citizen in Chippewa County. The Conservancy’s research is featured in numerous newspaper and magazine articles. Most DNR biologists quoted by the media continue to deny cougars are found in Michigan or state that any cougars actually detected must be escaped or released pets.

2002 – DNR biologists determine that livestock were attacked by a large cat, probably a cougar, at two properties in Kalkaska County. Permits are issued to four landowners authorizing them to kill or trap a large, feral cat. Television and newspaper articles document the incidents and question the appropriateness of the agency’s actions.

2003 – In response to public requests the MWC publishes a 54-page Field Guide to Detecting Cougars in the Great Lakes Region. The Conservancy, having received many requests from local police agencies, publishes a brochure entitled “Living With Cougars In Michigan.” The Conservancy provides training on cougars for the statewide membership of the Michigan Association of Animal Control Officers.

November 2003 – The National Park Service (NPS) posts warning signs at all of its trailheads in Sleeping Bear Dunes National Lakeshore. Titled “You are A Visitor In Cougar Habitat,” the sign emphasizes some important do’s and don’ts if one encounters a cougar. The NPS takes this action in response to a long history of sightings by its own staff and citizens, research in the Lakeshore by the MWC, and a close-encounter with a cougar by one of the Lakeshore’s volunteers.

2003/04 – Bay City Times and Traverse City Record Eagle become first newspapers to take editorial positions calling for the DNR to acknowledge the wild cougar population and research the predator so that Michigan citizens know how to be safe in the outdoors.

January 2005 – MWC releases videotape from Monroe County confirming (with absolute proof) two cougars, 5 ½ and 6 ½ feet long. Taken on April 24, 2004 by Carol Stokes, the video provides evidence suggestive of breeding by cougars. Two professional video analysts conduct split-screen size comparisons and field tests to confirm the size of the two cats.

February 2005 – The DNR releases DNA evidence that a motorist hit a cougar in southern Menominee County. Hair taken from the car bumper by a State Trooper tests positive for cougar. The location is just 7 miles from a cougar scat picked up in 2002, and 11 miles from where blood covered bone fragments from a cougar were recovered in 1984. The DNR states the DNA confirms just one animal, not a population.

February 2005 – DNR Director Rebecca Humphries is quoted in an article in Woods-N-Water News as follows: “We have been portrayed as not believing they are in the state. We do. We have a sighting log we keep and we encourage people to contribute to it, so clearly we believe there are cougars being sighted in Michigan. What we’d like to do is confirm there is a breeding population in Michigan, and we just haven’t been able to do so. For years, there had been reports of cougars sightings in individual files of biologists in the field. Some had taken good notes, and some had not. But there was no consistency in how we kept the records.”

April 2005 – Just two months after the DNR press release on the cougar struck by a car in Menominee County, Doug Wagner, DNR wildlife biologist, appeared on “Ask the DNR,” on Marquette Public Television. In responding to a viewers question asking what was the estimate of Michigan’s cougar population, Wagner responded, “ my estimate is zero.”
September 2, 2005 – A detailed field investigation and necropsy by the Michigan Wildlife Conservancy confirm independent findings by Jackson County Animal Control Officers that a cougar killed a 1,200 lb, 26-year-old horse in Parma Township. Bite and claw marks on the horse, cougar tracks at the scene, and sighting of a large cougar less than two miles away by the Township Supervisor leave no doubt about the cause of death. Interviews with local residents indicate previous reports of cougar sightings in the area were ignored by county and state officials.

September 22, 2005 – Following news reports of the cougar attack on the horse in Jackson County, Ray Rustem, DNR Natural Heritage Program Supervisor is quoted in the Jackson Citizen Patriot as saying: “There’s no way to track these animals; we have no expertise. He’s on private property and we’d have to get permission from each property owner.” This statement reflects the DNR’s admission that they have no plans to conduct meaningful field research on this endangered species.

December 2005 – A detailed field investigation and necropsy by Berrien County Animal Control Officers, a local veterinarian, and the Michigan Wildlife Conservancy confirm a cougar injured a full-grown horse near Watervliet so severely it had to be euthanized. The necropsy is conducted in full view of more than 15 newspaper and television reporters and police officers. Distinct claw and bite marks on the horse indicate no animal but a cougar could have attacked the horse. However, the DNR states the horse was attacked by coyotes or dogs.

2005/06 – Jackson Citizen Patriot, South Bend Tribune, St. Joseph Herald Palladium and Dowagiac Daily News join the list of daily newspapers to take editorial positions on Michigan cougars. The South Bend Tribune asks DNR why they are intent on making fools of Michigan citizens.

January 2006 – Berrien County became the first unit of government in modern history to declare a public safety advisory cautioning residents to be aware that a cougar attacked a horse in the county, and is potentially dangerous. Three Michigan legislators host a public meeting in Berrien County about cougar evidence in southwest Michigan.

April 2006 – The American Midland Naturalist publishes a paper titled Detection and Classification of Cougars in Michigan Using Low Copy DNA Sources by Dr. Brad Swanson of Central Michigan University and Dr. Patrick Rusz of the Michigan Wildlife Conservancy. The study summarizes the first peer-reviewed, scientific evidence of multiple cougars East of the Great Plains other than Florida. The study provides DNA evidence of eight cougars in Delta, Dickinson, Houghton and Menominee counties in the Upper Peninsula, and Alcona, Emmet, Presque Isle, and Roscommon counties in the Lower Peninsula.

June 2006 – Battle Creek Police issue a public safety alert, after police officers report seeing cougars on separate occasions, including a mother and two cubs.

August 10, 2006 – The Michigan Wildlife Conservancy presents its peer-reviewed DNA evidence of cougars to the Michigan Natural Resources Commission and emphasizes that part of Section 324.36502 of the Michigan Endangered Species Act states: “The Commission shall perform those acts necessary for the conservation, protection, restoration, and propagation of endangered and threatened species of fish, wildlife and plants.” The Conservancy expresses its belief that this language requires the Commission to conserve, restore and propagate the cougar, and that the actions of the Commission and DNR to date on cougars are contrary to the intent of voter-approved Proposal G which calls for science-based wildlife management.

October 5, 2006 – At a meeting of the state’s Natural Resources Commission (NRC) the DNR acknowledges the peer-reviewed evidence of cougars in Michigan compiled by the MWC and Central Michigan University. The NRC and DNR also pledge to treat citizen reports and/or complaints of cougars seriously. DNR Director Rebecca Humphries apologizes for any disrespect shown to citizens reporting cougar information in the past. However, the DNR does not commit to developing a management plan for the cougar as required by the Michigan Endangered Species Act.

October 25, 2006 – In a “White Paper” entitled Hiding The Cougar: Denying The East Its Apex Predator, the MWC concludes that the state’s Natural Resources Commission (NRC) and Department of Natural Resources (DNR) are violating the Michigan Endangered Species Act, and charges that state officials have refused to take steps to restore the cougar despite evidence that the big cats have long been found in Michigan. The MWC’s White Paper examines the arguments that DNR personnel have used to justify ignoring cougar evidence, and contends the agency is still not “connecting the dots” and complying with state law.