In the space of a year and a half, No. 239 zigzagged her way through northeastern California between eastern Shasta Valley in Siskiyou County and the Madeline-Ash Valley area of Lassen County, an airline distance of about 120 miles. She made the round trip and side trips almost three times, covering a total of 1,800 miles.

No. 239, according to the Department of Fish and Game, is a 600-pound adult Roosevelt elk cow that resides part of the year with about 110 other elk along the western slopes of the Cascade Range between Shasta Valley and Butte Valley.

How does the DFG know so much about the personal comings and goings of this particular ungulate? It turns out she not only wears an ear tag with the number 239 on it, but also a global positioning system, or GPS, transmitter collar.

Richard Callas, DFG senior wildlife biologist in Siskiyou County, said the cow is one of seven wandering northeastern California with the GPS devices — a modern tracking collar that uses satellite triangulation to digitally record nearly precise earthly locations of an animal three or more times a day for months on end.

With the financial backing, and some hands-on assistance, of the Rocky Mountain Elk Foundation, Callas and other DFG personnel captured the seven GPS elk and an eighth now fitted with an old-style transmitter collar in early February in the third year of a study of the north state's expanding elk herds.

Over a period of years, Callas said, the DFG hopes to capture additional elk and collar them with GPS units. Fish and Game said the relatively new GPS tracking system, also being used on deer, helps the DFG identify the preferred seasonal habitats of the species and to compare that habitat with habitat mapping done by various agencies, including the department.

"We're testing our mapping against information provided by the experts — the animals themselves," Callas said.

The DFG said it has used the data to deal with proposed habitat changes, such as a recent U.S. Forest Service plan for a large controlled burn that the DFG saw as having potential for harm to the Great Basin vegetation used by deer and elk.

The GPS collaring process involves "net-gunning" elk from a helicopter and attaching the collars and ear tags. A year or more later, a transmitter button is pushed, the collar falls to the ground and the data from its daily logs are downloaded into a computer that turns them into dots on a map.

In the case of No. 239, the map dots were spread over such a large area that at first biologist Callas thought there was a malfunction in the collar or in the computer program. Later, cross-checking proved the dots were valid.

He said the cow elk spent most of the winter along the west slope of the Cascade Range east of Montague in Siskiyou County, moved to Butte Valley in the spring, then further east to Tionesta for the summer, later south to Egg Lake, then east over Adin Pass and Highway 299 and, finally, southeast to Madeline.

The animal nearly completed the full round trip three times over the space of 18 months, with airline miles between map dots adding up to "conservatively 1,800 miles," Callas said.

"We know that young bull elk tend to roam a lot, like the one we collared that went north to Crater Lake in Oregon," said Callas.

But, he admitted, the behavior of No. 239 was a big surprise. The animal, which seemed to take a liking to the Madeline area for summer months, used an almost identical route to and from the Lassen plains all six times it moved, he said.

Fish and Game said it has collars on elk in the Shasta Valley area, in the Egg Lake area northwest of Big Valley and in the Devil's Garden of Modoc County.