PORTLAND, Ore. (AP) — Two backcountry skiers were killed and two others were seriously injured when an avalanche in eastern Oregon's Wallowa Mountains hit a party of eight, officials said. 
  
 The deaths mean at least 12 people have died in avalanches nationally this season, including six since Sunday. 
  
 Low clouds and poor visibility grounded a rescue effort for the injured skiers late Tuesday night, Baker County Undersheriff Warren Thompson said. Two medics were with the man and woman. 
  
 Four unhurt skiers were being brought out by snowcat, a large tracked vehicle that can maneuver on snow, Thompson said. 
  
 The snowcat was unable to reach the injured skiers because of the incline of the slope they were on, the undersheriff said. The injured woman suffered two broken legs and a shoulder injury while the man had a broken thigh bone, Thompson said. 
  
 Two National Guard helicopters, one each from Oregon and Idaho, hoped to resume rescue efforts Wednesday, Thompson said. They spent the night at the Baker City Airport. Ground rescue crews also worked to get closer to the site. 
  
 Most of the skiers were from the Seattle area. Officials weren't releasing names until relatives could be notified. 
  
 The avalanche hit at about noon Tuesday as the eight skied in the remote and mountainous area near Cornucopia, Baker County Sheriff Mitch Southwick said in a statement. 
  
 Connelly Brown, the owner of Wallowa Alpine Huts, said the skiers were part of a backcountry skiing group organized by his Joseph-based company. The group included two guides and six skiers. 
  
 Brown said a guide contacted him by cellphone after the avalanche hit, reporting two possible fatalities and two skiers with broken legs. The skiers were on a guided five-day, four-night trip, he said. 
  
 The avalanche came down on the third day of the trip, Brown said. Later that night, as on previous nights, the group planned to sleep at the Schneider Cabin, a historic miners' log cabin on the south side of Cornucopia Peak. 
  
 Brown said the clients and the guides were all "fit, proficient downhill skiers." The guides were certified by the American Institute for Avalanche Research and Education and trained by the American Mountain Guide Association, he said. 
  
 "From the description, it sounded like they were traveling and the avalanche came from above and caught them by surprise," Brown said. 
  
 The avalanche occurred in the southern part of the Wallowa Mountains, near the Idaho border. The Wallowas are known as the "Alps of Oregon." With their rocky peaks and deep ravines, the mountains are popular with backcountry skiers, hikers and horseback riders. 
  
 A bulletin from the Wallowa Avalanche Center on Thursday warned that "new snow is not bonding well to the old surface." The bulletin mentioned a recent report from the southern Wallowas of a skier triggering a small avalanche in which no one was caught. 
  
 Elsewhere, Kevin Kuybus, 46, of Highlands Ranch, Colo., was found dead Tuesday after an avalanche outside a Colorado ski area. Another avalanche near Kebler Pass, Colo., killed a snowmobiler Monday. 
  
 The death toll includes two people who died in slides in Utah over the weekend. On Sunday, Ashleigh Cox, 21, of Colorado Springs died after being caught in an avalanche while she was snowshoeing Saturday in American Fork Canyon. About 90 miles away in Sanpete County, Clint Conover, 36, died after being buried in a slide Sunday while snowmobiling. ||||| Officials with the Baker County Sheriff’s Office said two cross-country skiers were killed about noon Tuesday in an avalanche in the south Wallowa Mountains near Cornucopia, about 10 miles northwest of Halfway. 
  
  
  
  
  
 Sheriff Mitch Southwick said eight people were skiing together when the avalanche hit, killing two and seriously injuring two others; four skiers were unhurt. The two injured skiers suffered broken bones, Southwick said. Unconfirmed reports said a woman suffered two broken legs and a man one broken leg. 
  
  
  
  
  
 Southwick said the skiers were from Seattle and were clients of the outfitters Wallowa Alpine Huts in Joseph. The company conducts wilderness ski tours in the Eagle Cap Wilderness; clients stay overnight in yurts or the historic Schneider cabin. Southwick said one survivor used a cell phone to call 911 to report the avalanche. 
  
  
  
  
  
 A LifeFlight Helicopter was dispatched but could only get within about a half mile of the scene, Southwick said. Members of the Panhandle Snowmobile Club and helicopters from the Oregon and Idaho National Guards were also dispatched to assist in the rescue and recovery. 
  
  
  
  
  
 Much of Oregon and Washington saw heavy snowfall during the past week, and the Wallowa Mountains saw temperatures warm above freezing Tuesday in some locations, with a forecast for heavy snow and rain. 
  
  
  
  
  
 Experts say the snow that fell recently fell is very dense and fell onto much lighter snow that fell last week during the much cold weather, making it more susceptible to sliding. 
  
  
  
  
  
 Jeff Ward of the NW Avalanche Center testing the snowpack near Stevens Pass Tuesday. 
  
  
  
  
  
 On Tuesday, the Northwest Avalanche Center in Seattle issued an avalanche warning for the Washington Cascades west of the crest and for the Mount Hood area for Tuesday night and Wednesday. 
  
  
  
  
  
 The most recent avalanche death in Oregon occurred in January 2010, when a snowmobiler died in near Paulina Peak in Central Oregon. 
  
  
  
  
  
 According to the Oregon Nordic Club "avalanches tend to happen on slopes angled between 30 and 50 degrees. A slope may become avalanche prone after receiving heavy snow of an inch an hour for several hours. Rain, strong winds, and rapidly increasing temperatures can cause snow to shift making it unstable." 
  
  
  
  
  
 --Stuart Tomlinson 
  
  
  
  
  
 News researcher Lynne Palombo contributed to this report. |||||

Write a summary.
– An avalanche in Oregon's Wallowa Mountains yesterday killed two skiers and seriously injured two others, officials say. A group of eight people was skiing in the south part of the mountain range near Cornucopia when the avalanche hit; the other four were unhurt, the Oregonian reports. Oregon and Washington have seen heavy snowfall over the past week, and experts say the snow has been dense—and has fallen onto lighter snow, making it more likely to slide. Avalanche warnings are in effect for parts of the Washington Cascades and the Mount Hood area. The group was on the third day of a guided backcountry outing meant to last five days, and was comprised of two guides and six skiers, the AP reports. The owner of the company that organized the trip says they were all "fit, proficient downhill skiers" and that the avalanche "caught them by surprise" from above. The two injured skiers—one with two broken legs, another with a broken thigh bone—are still on the mountain, with medics, until conditions clear so rescue efforts can resume. So far this season, 12 people have died in avalanches, six of those since Sunday.