That`s it for Mopetown. It doesn`t exist anymore.

The last family in the last house in Mopetown has finally moved out. They had to. One side of their simple wood-frame home at 1845 W. 31st Pl. simply crumbled and collapsed. The old place couldn`t remain standing any longer.

Understandably, Mary Wilkens, 71, the last housewife remaining in Mopetown, left with tears in her eyes.

''We`ve lived here in Mopetown for 60 years,'' she said. ''I loved it down here. We had all sorts of privacy. We were the hidden neighborhood. The kids could run free, you could move and breathe and never lock a door.

''It was paradise even though nobody was rich. But it`s over now. Mopetown has disappeared into a dream and I`m still alive. I`m lost not living down here anymore.''

Tucked in between the Bridgeport and McKinley Park neighborhoods, from Ashland to Hoyne Avenues, from 31st Place to 33rd Street, Mopetown was a hard place to find. Few strangers, even if they knew the unbeaten path that led there, ventured in-for Mopetowners were not only tough, they stuck together.

Even recently, while the one last home in Mopetown was still inhabited, precinct captains could never find it, the police could take two hours to figure out how to get there.

''Forget ordering a pizza,'' said Wilkens` son, Ralph, who was raised there. ''You could never get one delivered because they could never find Mopetown.''

Nobody knows how Mopetown got its name. Those living there didn`t much care. They were Mopetowners, not Mopes. Nobody dared call them that.

It was a blue-collar, hard-working, hard-drinking kind of place, where little cottages were crammed with lots of kids, the women were good-natured and long-suffering and dogs roamed free. None of the streets were paved;

sidewalks didn`t exist; nobody carried a key to their front door; the Kubera family`s monkey scooted loose around the neighborhood; prairie flowers grew wild all around; and if a man had a bag of Bull Durham tobacco, he shared it with his neighbor.

In the good old bad days of the Depression, back in the `30s, many of the families made ends meet by brewing white lightning in their homes, and those households which sold it were called ''blind pigs.'' Every fourth house in Mopetown was a blind pig.

Mary Wilkens remembers that people ''walked track,'' referring to the habit in Mopetown of going along the nearby railroad tracks to pick up coal that had fallen from a train`s coal car. They helped themselves to fruits and vegetables that had fallen from the freight cars.

''I remember my father with a potato sack thrown over his shoulder, full of coal,'' said Janet Hopkins, who grew up a stone`s throw from Mopetown. ''I think it held 100 pounds. And at least three times a week, he went and picked coal off the tracks, as we had no money and this was the only way to heat our cold-water flat.''

It was during those days that she frequently visited the home of her uncle Dennis Starr, known unofficially as the ''Mayor of Mopetown.'' She would often find his wife, Aunt Ellie, standing in the kitchen over a fire-burning stove, wearing her apron and Uncle Dennis` shoes, cooking homemade soup in one pot and homemade white lightning in the other.

''It was a little village inside the big city,'' said Larry Brewerton, who grew up there and lives only four blocks away. ''Mopetown grew up as a collection of cottages inside a triangle surrounded by the tracks of the Sante Fe and the Chicago and Alton railroad lines. The people were Irish, German, Italian, Polish, English and Bohemian-all kinds. We all had nothing, so we didn`t miss it.

''I think of my youth there and realize how wonderful it was. Never could a suburb have that atmosphere. It was purely a city neighborhood that was unique. It is gone now but etched forever in my mind.''

With the collapse of the last house in Mopetown, and the departure of the Wilkens family, the last of Mopetown has faded away. It is lost-like many a neighborhood in the city that has disappeared-to everyone except the old-timers who grew up there, moved away and later returned to find the old neigborhood gone.

''When my parents left recently, it was the last of Mopetown,'' said Ralph Wilkens. ''I have great memories of this neighborhood. Mopetown was Mopetown until they built the Stevenson Expressway, which wiped out much of it. After the expressway, there were six houses left. Then there were four. Then there were two. Then there was just my mom and dad living there and now there is nothing. It`s all gone. All that remains is memories.''

The last house in Mopetown stands empty and dark, the other three sides about to fall down too.

An expressway arches over where Mopetown used to be. Weeds grow up through cracked cement where children used to play. Trucks grind their gears and the wind whistles where neighbors used to shout to each other over backyard fences.

''They turned the last light off in Mopetown,'' said Harold Hopkins, who spent much of his youth in the neighborhood. ''When the last light goes off, it`s over. It`s joined with history now, kept alive only by dreams and memories. Those memories are happy ones.''