A 26-year-old Anchorage man accused of opening up on a Russian River grizzly bear with an assault rifle then leaving the animal to die a slow death has been charged with six misdemeanors.

Charging documents say Michael B. Oswalt of Anchorage at first denied shooting the bear but later admitted to firing three or four times in the direction of the sow and her cubs.

Authorities say they later determined -- based on 26 unfired rounds found in a 30-shot clip still stuffed in Oswalt's Chinese-made SKS 7.62X39 mm semi-automatic rifle -- that four shots were fired at the sow. At least two slugs were recovered from her body.

One of those slugs, according to charging documents, has been matched by ballistic tests to Oswalt's weapon.

When the sow was shot, she was accompanied by three yearling cubs. For much of the summer, to the delight of wildlife viewers, the nearly adult-size cubs had been prowling the banks of Alaska's most popular salmon stream with their mother.

Though the cubs were not injured in the shooting, authorities continue to have concerns about the survival of the trio without the sow around to try to keep them out of trouble.

Kenai National Wildlife Refuge deputy manager Jim Hall said Thursday that the yearlings dangerously intermingle with people, in part because people show too little respect for the animals.

This week, Hall said, "they tore into another backpack left on the ground.''

Wildlife biologists worry that if the bears continue to get treats like that they will lose all fear of people. If that happens, someone could be forced to shoot one or more of the animals in self-defense, or the bears will have to be tranquilized and relocated before they hurt someone.

Relocating the bears would solve the Russian River problem, but wouldn't necessarily help the bears. Most good bear habitat in Alaska is already occupied by resident grizzlies likely to kill intruders.

The yearlings have other problems, too. Biologist Jeff Selinger, Kenai wildlife manager for the Alaska Department of Fish and Game, was at the Russian River Thursday trying to dart one of them so he could remove multiple fish hooks she'd somehow gotten stuck in her foot.

Exactly why their mother was shot, meanwhile, remains something of a mystery. Oswalt, according to the charging documents, gave authorities multiple stories about what happened along the Russian near its confluence with the Kenai River on the morning of July 31.

When first contacted about 8 a.m. that day by Kenai National Wildlife Refuge officer Clayton McDermott, Oswalt -- according to the charging documents -- admitted having fired a burst of gunshots around 7:30 a.m., but added "that he did not shoot at a bear.''

McDermott got the serial number off Oswalt's rifle anyway and forced the 26-year-old, lifelong Alaskan and his fishing buddy, Aaron Carter, to provide identification. The dead bear turned up the next day when refuge officer Chris Johnson was called to investigate aggressive behavior on the part of the cubs. They were found to be guarding the carcass of the sow.

Two days later, according to charging documents, Fish and Wildlife special agents Rory Stark and Steve Oberholtzer contacted Oswalt in Anchorage, where he told them a bear story different from that given McDermott. In this version, the charging documents say, the sow "stood up, looked and came at them, so he shot three or four times toward the bear.''

Oswalt continued to insist, however, that he was "98 percent sure he didn't hit any bears.''

Carter, interviewed separately, contradicted most of Oswalt's statement. According to the charging documents, Carter told investigators that the bears didn't start moving toward the two men until after Oswalt's first shot, that the bears didn't appear to be aggressive, and that "after they ran away, Oswalt said he thought he hit one of the bears.''

Neither Oswalt nor Carter could be reached for comment Thursday.

Authorities said they obtained the SKS semi-automatic rifle from Oswalt at his Anchorage apartment.

The six Class A misdemeanors with which Oswalt has been charged in connection with the shooting of the sow are: taking a brown bear in a closed area, taking a brown bear during a closed season, taking a female bear with cubs, failure to salvage the hide and skull of a brown bear, hunting brown without the proper tag, and reckless endangerment.

He is scheduled to appear in Anchorage District Court on Aug. 30.

Daily News Outdoor editor Craig Medred can be reached at cmedred@adn.com .