The kids will soon be out of school, and millions of families across America are planning a trip to Yellowstone National Park.

What most of them will find there is Old Faithful geyser and, well, millions of other families.

In early May, I had an opportunity to see a different side of Yellowstone, and a chance to experience the winter that never came to Brookings.

My spring vacation, in fact, turned out to be a descent into winter. I left Brookings during one of the coldest weeks wed had all year. By the time I reached the Illinois Valley, the rain was already looking suspiciously chunky.

I was soon to learn that the main difference between winter and spring in Yellowstone is that the roads are plowed, but not necessarily open.

Moose meadows that are green even in late summer were gray in May. Yellowstone Lake was completely frozen over. Spring finally arrives in Yellowstone about the time summer officially begins everywhere else.

While driving across the plains of Eastern Washington, I listened to Garrison Keillor explain on A Prairie Home Companion that you can tell winter is over in Minnesota when people switch to their spring parkas. Ditto for Yellowstone.

Locals, however, call it our time in the park, the period between March 15 and June 15, when the snowmobile crowd is gone, but the summer tourists have yet to arrive.

Fewer people means more wildlife, I discovered, and some all-too-close encounters with bison.

As I was creeping past a bison that could have pinned me to the hillside with one flick of its massive head, in a part of the park closed to tourists no less, I had to ask myself what I was doing there.

My mission was to deliver my son to Yellowstone by May 1 to accept a summer job.

What we found, besides lower gas prices everywhere, is that few people besides employees go to Yellowstone in May.

In fact, not much of the park is open in the spring. The north entrance near Gardiner, Mont., is open year round, as is the road along the north border of the park to the northeast entrance and Cooke City, Mont.

The loop road around the park is open to snowmobiles and snow coach tours from late December through mid-March. Rooms are also available at the Old Faithful Snow Lodge and the Mammoth Hot Springs Hotel.

Cross-country skiers and snowshoers help make winter one of the busiest seasons for border communities, where a Super 8 motel can be booked up a year in advance.

Not so in May, when all park lodging is closed. Most of the guests in our Super 8 were reporting the next day to the offices of AmFac, a park concessionaire.

Bed and breakfast operators across the west should note that the four Super 8s we stayed in had no trouble providing plenty of towels and toilet paper, and all had good heating and air-conditioning systems.

Comfortably settled in our budget motel, we had the rest of the afternoon to kill in the park.

We drove through the famous Theodore Roosevelt Arch, dedicated by Teddy himself in 1903, at the north entrance.

Five miles south of Gardiner, we stopped and hiked the boardwalks along the spectacular travertine terraces of Mammoth Hot Springs.

The formations, reminiscent of classical temple ruins, are formed when hot water emerges from the hillside and deposits calcium carbonate, the same mineral that makes cave formations.

Mammoth Hot Springs changes constantly as water ceases to flow to some formations and they turn gray and begin to crumble.

Terraces filled with blue and green pools when I visited the park five years ago were empty and forlorn-looking now.

Water was emerging in torrents from the south end of the terraces, however. We could see where the travertine was coating fallen pine needles and building new bright-white terraces day by day.

For those who cant hike the boardwalks, the upper terraces are easily accessible from a driving loop.

Mammoth Hot Springs is also the location of historic Fort Yellowstone, which protected the worlds first national park from 1886 to 1916.

A visitors center is open year round there, and provides an excellent introduction to the park. Herds of elk also cluster around the buildings.

Late in the afternoon, we decided to drive the 21 miles south to Norris Geyser Basin. The parks speed limit is 45 mph, but the road is so twisty and full of potholes, one can rarely drive that fast.

A ranger warned us about potholes that could swallow a small imported car, and she wasnt kidding.

Add in tourists blocking the road to look at wildlife in the summer, and a little time to look at wildlife yourself, and it takes about an hour to go 20 miles in Yellowstone.

We didnt see much wildlife that day. The elk were about the only creatures that didnt seem to be bothered by the near-freezing rain.

We were thrilled to see two bison in the distance, and wondered what the plains looked like when there were still millions of the majestic creatures.

We encountered isolated hot spring pools along the road. A few miles north of Norris, we passed by Roaring Mountain, an entire hillside of fuming steam vents.

Norris is one of the most active geyser basins in the park, and was the only one accessible to cars that day. Roads south of that point were still closed by snow.

We didnt expect to see Steamboat Geyser erupt. The worlds largest geyser, it can reach heights of more than 300 feet, but it only erupts every couple of years or so. Minor 75-foot eruptions are more frequent.

Steamboat was bubbling away with six-foot splashes out of its pool, but didnt do anything spectacular when we were watching.

We also just missed the eruption of Echinus Geyser, which looks like a hot spring part of the time, but can put on a truly unique water show every hour or so.

The geysers, like Mammoth Hot Springs, were curiously inactive compared with my last visit to Yellowstone.

I wondered if that was because most of the water was locked up in snow, but books told me water coming to the surface fell as rain hundreds, or even thousands of years ago.

Maybe the lack of geyser activity was just bad luck, but we didnt even get to see Minute Geyser erupt. Perhaps it only erupts for one minute out of every year.

When even Constant Geyser turned out to be constantly inactive that day, my son could only laugh at my frustrated reaction.

The hot pools were beautiful, but were often obscured by clouds of sulfurous steam caused by the interaction of boiling water and freezing air.

Half of the Norris basin is really one big boiling lake, covered with an inch-thick crust. Geothermal features come and go so quickly there that it isnt worth giving them names.

We finally saw a small 6-foot high geyser erupt. I was to learn however, that geysers are only a small part of the wonders of Yellowstone National Park.

In part two of this story, I risk life and limb for a glimpse of those wonders.