LYONS, Colo. — The number of missing in Colorado’s flooding dropped dramatically to 200 as authorities reached more victims, and residents evacuated from the hard-hit canyon town of Lyons were allowed past a National Guard roadblock Thursday to salvage what they could from their homes.

“We’re a little anxious. We’ve never gone through something like this before,” Gloria Simpson said as she waited in a long line of cars to Lyons, a community of about 1,600 in the Rocky Mountain foothills. A raging St. Vrain River cut a swath through its streets Sept. 19.

Guard troops allowed residents a few hours to inspect their homes and grab belongings before nightfall. Simpson hoped to leave with anything she could from her 81-year-old father’s streamside home.

Mystie Brackett wanted to remove spoiled food from her refrigerator and get some clothes.

“It’s a weird feeling,” Brackett said. “There is survivor’s guilt because my house is fine and my business is fine.”

Across the Front Range, the number of people unaccounted for plunged from a high of 1,200 to about 200 thanks to rescues and the restoration of phone service in more areas that allowed residents to contact family and authorities.

Six people died, and two Larimer County women were missing and presumed dead. Larimer County reported Thursday that a third person, a 46-year-old Drake man, was missing and presumed dead after his home was washed away.

In a sign of things to come, Trail Ridge Road through Rocky Mountain National Park — a key supply route to the flood-ravaged town of Estes Park — was temporarily closed because of snow early Thursday. The high-elevation road normally shuts down in October for the winter.

Officials urged residents in stranded towns to leave before the snows hit but acknowledged hundreds are determined to stay.

Larimer County Sheriff Justin Smith said he was impressed by residents in one area who are rebuilding their access road with shovels and pick axes. Road repairs likely will take months and in some cases will consist of a single dirt lane before winter.

To the east, Colorado’s flooding triggered at least two significant oil spills. Regulators said 323 barrels of oil spilled from an Anadarko Petroleum tank farm near Platteville. A second Anadarko tank spilled 125 barrels into the South Platte River.

Flooding along the South Platte River pushed into western Nebraska but caused little initial damage.

Amtrak said its Chicago-to-San Francisco California Zephyr train will be detoured through early October because of track damage in the Front Range foothills. Passengers will take buses to Glenwood Springs and Grand Junction, Colo., and to Green River, Helper and Provo, Utah, until repairs are completed.

The White House said Thursday that Vice President Joe Biden and his wife, Jill, will survey recovery efforts in Colorado on Monday.