As the twin metal gates slid open and the line of SUVs crossed over the cattle guard, I thought of Jurassic Park.

A caravan of vehicles, winding through a primordial sanctuary where herds of immense, ancient creatures grazed? Hold onto your butts. The cars crept along, a line of brake lights going 5 mph through flower stalks as tall as your head. Each driver peered into the woods for a flicker of movement, a change in the light.

And then we were ambushed from all sides—by reindeer.

Caribou, technically. Then bison, Roosevelt elk, mountain goats and bighorn sheep—all grazing on 435 acres of freshly mowed pasture and fern-strewn forest in the shadow of Mount Rainier.

The ungulates are residents of Northwest Trek Wildlife Park (11610 Trek Drive E, Eatonville, Wash., 360-832-6117, nwtrek.org), funded by the citizens of Pierce County, Wash., about a three-hour drive from Portland.

Typically, the park offers open-air Jeep tours. In late May, it pivoted to motorcades ($80 per vehicle, reservations only; most of July is booked, so aim for August): a dozen cars and trucks, each load of visitors socially distanced, the tour guide piped in over the car stereo.

I'm familiar with drive-thru zoos from a Florida youth misspent at Lion Country Safari. Most states have their own variation on the car safari (Oregon is no exception, with giraffes off I-5 in Douglas County). But the vibe at Northwest Trek is different: more Ansel Adams than Doc Antle, in no small part because the animals are Pacific Northwest species. There's no substitute for the awe inspired by the sight of a herd of elk grazing in the glacial valley of a national park—but we're all making do these days, and watching a bison bull saunter by your car still carried a thrill. (I never did catch a glimpse of a moose, but they're in the compound, too.)

And then there were the caribou. I'd never gotten close to one before, and they were a delight: cow-eyed and molting winter fuzz from their backs and antlers, the tendons in their feet clicking rhythmically as they ambled toward visitors. They wandered between vehicles, sometimes bringing the caravan to a halt by joining the procession themselves. When the year began, I did not expect my first traffic jam to be caused by an arctic deer herd. Finally: a pleasant surprise.