( CNN ) -- Blistering hot temperatures will blast the normally tepid Pacific Northwest again Thursday as dozens of wildfires burn across large sections of the western United States . The mercury is expected to soar near triple digits in Portland , Oregon , with Seattle forecast to reach the lower 90s , the National Weather Service said . The coastal region is roasting under an excessive heat warning . At least 70 large fires were burning across 13 states west of the Mississippi River , according to the National Interagency Coordination Center . California had the most with 13 , followed by Nevada with 12 and Idaho with 10 , the center said . The Marines joined the fight on Wednesday , with helicopter units from California joining U.S. Air Force Reserve and Air National Guard units from Colorado , Wyoming , North Carolina and California in fighting the fires by air . The Marine units will help fight fires around San Diego . In California alone , 8,000 firefighters were fighting a dozen fires , the state Department of Forestry and Fire Protection said Wednesday . The state issued a burn ban , saying only some campfires are allowed . Conditions could worsen in some places over the next few days . The National Weather Service said a weather pattern developing in parts of Oregon could produce conditions favorable to `` explosive fire growth . '' In central Washington state , the wind-whipped Taylor Bridge Fire had scorched some 22,600 acres and destroyed at least 60 homes , fire officials said . One of those structures was the home of Elaine Burt , who unsuccessfully tried to get past firefighters to save her dogs and other animals at her home , according to CNN affiliate KING-TV.. After the initial heartbreak of being told all of them were gone , she learned Wednesday that Hannah , one of her dogs , and six of her pigs had survived . `` Oh Mama ... hi mama , '' Burt said when she saw her sow at the Kittitas County Fairgrounds . `` One , two , three , four , five , yup , that 's all her little babies . '' Washington Gov . Chris Gregoire declared Kittitas and Yakima counties to be in states of emergency , according to a written statement from her office . The Washington National Guard will provide air support to the Department of Natural Resources , which is in charge of statewide firefighting efforts . Authorities have already evacuated around 900 people near the Taylor Bridge Fire , the governor 's office said . No injuries were reported . More than 900 firefighters were battling the fire near Cle Elum , Washington , said Rex Reed , the incident commander . The Incident Alert System showed the blaze was 25 % contained early Thursday . The weather was `` cooperating '' Wednesday , he said , referring to calmer winds , but firefighters have their work cut out for them the rest of the week . Hot and dry conditions are expected . `` Unless Mother Nature helps us out here , we 're going to be fighting this a while , '' Joe Seemiller , a captain with Kittitas County Fire and Rescue , told CNN affiliate KOMO-TV . Elsewhere , more evacuations were under consideration near Featherville , Idaho , where more than 800 firefighters were trying to get a hand on the sprawling Trinity Ridge fire . The fire grew significantly since Tuesday , burning more than 68,000 acres and forcing authorities to call an emergency meeting of residents of Featherville and nearby Pine to discuss possible evacuations . Near the border between Oregon and California , crews were battling an aggressive southern run by the Barry Point Fire , which has torched some 59,000 acres of land in the two states , according to the incident command team 's website . With temperatures above 90 degrees , low humidity and wind gusts nearing 20 mph , the lightning-sparked fire has a high potential for further growth , the interagency center said , forcing the evacuation of homes in California , 15 miles south of the state border . Residents evacuate as hundreds of firefighters battle California wildfires . More than 800 firefighters and support personnel were working in Oregon and Nevada to corral the 436,600-acre Holloway Fire , the largest of the Western wildfires . It was ignited by a lightning strike on August 5 . Incident commanders said Wednesday that they hope to have the Nevada portion of the fire out on Wednesday . In Northern California , the Rush Fire had torched 101,000 acres since Sunday , the National Interagency Coordination Center reported . Meteorologists predict the dry heat will last into next week , not good news for firefighters . Any thunderstorms that pop up could present more bad news than good , since lightning strikes could spark more flames . As of Wednesday , wildfires have burned through 6.47 million acres this year , surpassing the 6.36 million acres burned by this date last year , according to the National Interagency Fire Center . The total acreage burned this year is about 3.4 million acres short of the record set in 2006 , when 1,801 fires burned a total of 9.87 million acres , according to center statistics . Neighbors vs. nature as wildfires rage in Oklahoma . CNN 's Ed Payne , Dan Simon , Moni Basu and John Fricke contributed to this report .
Dozens of fires are burning west of the Mississippi River . A burning ban is issued in California . More acreage has burned so far than last year at this time , national fire officials say . An Idaho fire could force more evacuations .