A US military fighter jet plunged from the sky near a popular Washington state recreation area on Saturday, erupting into flames and triggering a wildfire that sent thick black smoke billowing above the forest landscape.

Dramatic footage captured from the shoreline of Rimrock Lake recorded the moments after the aircraft went down, with stunned witnesses describing how they watched the pilot eject from the stricken jet seconds before the crash.

One woman filming the scene could be heard recounting the terrifying sequence of events after initially mistaking the ejecting pilot for a parachutist.

'Did he crash? There's a fire! He was spinning and I saw the parachute and thought, "Oh that's dangerous he's too close to a parachutist!" He just f***ing ejected!' she said in the video.

Reports from the scene indicated the aircraft was a US Navy F/A-18 operating along the famous VR-1355 low-level military training route through Washington state's rugged mountain terrain.

Emergency officials confirmed the pilot survived the crash after ejecting from the aircraft before impact.

Naches Fire said the aviator was transported to hospital after escaping the doomed plane.

'The pilot safely ejected and was transported to the hospital,' the department said in a statement.

Flames spread across vegetation near the crash site as firefighters, law enforcement agencies and federal resources rushed to contain the blaze before it could threaten nearby structures and campsites.

Naches Fire confirmed crews were dispatched to what it described as a 'downed military aircraft' near the lake.

'The crash sparked a wildfire that is currently being suppressed by helicopters and at least one engine from U.S. Forest Service - Okanogan-Wenatchee National Forest,' the department said.

Authorities moved quickly to evacuate campers from the area as smoke rose over the popular outdoor destination.

'The 1200 Rd system on the south side of Rimrock is closed and campers are currently being evacuated out of the area by multiple law enforcement agencies,' Naches Fire said. 'The area should be avoided for the foreseeable future.'

Fire crews focused much of their early efforts on protecting nearby buildings from the advancing flames.

'Our units have completed structure protection near the Bear Creek cabins and have just cleared the scene,' the department said.

'Our tender will remain on scene through the afternoon and will likely return tomorrow morning to support mop up operations of the fire.'

The Yakima County Sheriff's Office said military authorities had been notified and would be sending personnel and resources to the crash site.

Later on Saturday, the military confirmed the aircraft involved was an F/A-18 Hornet assigned to Marine Aircraft Group 11, 3rd Marine Aircraft Wing.

In a statement, Marine Corps Air Station Miramar said the cause of the accident remains unknown.

'The cause of the mishap is currently under investigation,' the statement said.

'To preserve the integrity of the investigation, no additional details are available at this time. Mishap investigations can take several months to complete, depending on various factors.'

The crash occurred in a scenic but rugged section of central Washington that attracts thousands of visitors each year.

The 2,546-acre Rimrock Lake reservoir sits along Highway 12 about 10 miles east of White Pass within the Okanogan-Wenatchee National Forest.

The region is popular with campers, hikers, anglers and backpackers, while the nearby Pacific Crest Trail crosses White Pass just a few miles from where emergency crews were battling the wildfire.