SEARSPORT, Maine — A fully loaded RV collided with another vehicle and flipped over on Routes 1 and 3 late Monday afternoon, injuring several people and forcing emergency crews to detour Memorial Day travelers around the busy stretch of highway for hours.

The crash, which happened just after 4:30 p.m. near the Searsport-Belfast town line, left a trail of debris for tens of yards down the road and it took crews about four hours to remove the demolished RV. None of the five patients appeared to have suffered life-threatening injuries, police said.

The occupants of the RV, Douglas and Cheryle Monson of Trenton, were treated at Waldo County General Hospital in Belfast and then released.

The driver of the second vehicle, 59-year-old Evangeline Brown from the Belfast area, was airlifted by LifeFlight helicopter to Eastern Maine Medical Center in Bangor. The two other occupants of Brown’s Subaru wagon — Tiffany Brown, 28, and Charlie Brown, 6 — were treated at Waldo County General Hospital and then released.

Searsport Police Chief Richard LaHaye Jr. said the crash remains under investigation. But LaHaye said the two vehicles were traveling in opposite directions on Routes 1 and 3 when they collided, causing the RV to tip over, slide down the road and flip onto its top. A Jeep Wrangler that was being towed by the RV remained at-tached and also was heavily damaged.

A Maine State Police accident reconstruction team was called in to assist in the investigation. LaHaye said there were several witnesses to the crash and police were still investigating the cause.

Holiday traffic on Routes 1 and 3 backed up but was able to continue moving because of a detour around the crash site. The road was still closed as of 9 p.m. as crews cleaned up the extensive wreckage.

“The debris field is pretty bad,” LaHaye said after 9 p.m. Monday.

Police, fire and rescue crews from Searsport and Belfast were at the scene.