August 10, 2001 11:00 pm

By Jayson Jacoby

For The Observer

The stretch of Interstate 84 near Ladd Creek has been deadly for a family of black bears.

On Tuesday night about 10 p.m. a westbound semi truck struck and killed a 5 1/2-year-old, 210-pound female bear near Milepost 272.

Thats close to where the freeway crosses Ladd Creek between North Powder and La Grande.

Its also almost the exact place where the bears mother and brother were hit and killed in October 1996, said Tara Wertz, a biologist at the Oregon Department of Fish and Wildlifes (ODFW) La Grande office.

Those three bears constitute the only ursine casualties on that stretch of freeway, at least according to ODFW records, Wertz said.

In the past few years one black bear was hit and killed by a car on Ore. Highway 86 near Oxbow, and another on Interstate 84 near Durkee, said George Keister, head biologist at ODFWs Baker City office.

Wertz said Ladd Creek is a natural travel corridor for many species of animals, including deer and elk.

Drivers need to be aware of that, she said.

Wertz suspects the bear that was hit Tuesday was foraging for berries and attracted by the cooler air along the creek.

In general, though, Wertz said bears are less likely than most other animals to cross a freeway.

ODFW biologists were first acquainted with the bear, known as No. 74, in March 1996, just three months after the cub was born to bear No. 18, Wertz said.

The mothers den, which No. 74 later inherited, is in the base of a big fir tree a couple miles west of the freeway, Wertz said.

Biologists implanted a computer chip in each of No. 18s three cubs, by which the animals movements could be tracked.

In October 1996 No. 18 and one of the cubs, a male, were hit and killed on the freeway, Wertz said.

Biologists tried to find the two surviving cubs, figuring that at the age of 10 months they were too young to survive without their mother, she said. But they never found either of the two cubs.

Then, in June of 1998, biologists working on a bear study treed a bear in the Ladd Creek area and shot her with a tranquilizing dart, Wertz said.

They were surprised to find it was No. 74.

They fitted her with a radio-transmitting collar, allowing them to follow the bears movements from an airplane.

No. 74 had taken over her mothers home range, which spans the area west of the freeway from near Ladd Marsh south to Ladd Creek, she said.

Biologists expected No. 74 would have her first litter of cubs this winter.

She was one of the larger female bears ODFW has ever found in Northeastern Oregon, Wertz said.

Only one sow weighed more 225 pounds and that bear was about nine years old, she said.

Female bears usually lose weight after bearing cubs, primarily because they have

to produce milk for their young for

several months even while hibernating, Wertz said.