Travis Decker — the Washington dad accused of brutally murdering his three daughters — has been seen in public, and cops say it’s only a matter of time before they catch him.

After a weeklong manhunt, cops now believe Travis is hiding out near Blewett Pass in the Wenatchee Mountains of Washington. It’s all thanks to a tip from hikers who spotted a sketchy man — who bore a striking resemblance to Decker — trying to be inconspicuous as he wandered around a trail in the Enchantments.

The Chelan County Sheriff says tracking teams jumped on the hikers’ tip — and sure enough, one of their chopper pilots eyeballed the lone hiker near the trail. But, the moment the pilot saw him, the man bolted.

Sheriff Mike Morrison told TMZ earlier this week it’s still unclear if Decker’s armed — but they’re hoping for a peaceful takedown.

But this manhunt’s no easy feat — Decker’s ex-military, trained in survival, and knows how to disappear in the wild for weeks.

As you know … Decker vanished after a court-ordered visit with his three daughters — Paityn, 9, Evelyn, 8, and Olivia, 5 — at the end of May.