OK, here's how it's worked out so far. I managed to find some approximation of a terrifying swamp-like area, although no cold ones.
The dwarves arrive, and stop the wagon right next to the river that teeming with skeletal longnose gar, skeletal sea lampreys, and about 3 other varieties of undead fish. I designate everyone to haul stuff over to that hill made of loam, to dig in and take up a defensible position.
The miner is savaged by an undead fish, all the other dwarves cancel retrive tool:interrupted by skeletal longnose gar.
Three more dwarves switfly follow the miner to his grisly fate; two farmers and a mason run off to the map's edge. One of the farmers is mauled to death by another undead fish.
The mason gets upset at this, throws a tantrum, and smashes the wagon to pieces. Then he gets eaten.
The farmer half-heartedly drags two barrels of food across the map, then falls conscious. Seconds later, he is devoured by another ambulatory river beast.
Starting over. Hopefully the wagon will spawn in a sensible place this time.