The park's ubiquitous bison.

Yellowstone National Park is a geological spectacle of the senses. The colors are vivid, the smells unforgettable, and the power of the geysers and waterfalls will fill you with awe.

The major attractions are all located along Grand Loop Road, which forms a circle, utilizing the 12-mile Norris Junction to Canyon Village Junction as its north boundary.

We spent a week at Canyon Village in a cabin that had a bed, desk and bathroom. The one luxury was an ice machine. However, the absence of TV and internet was insignificant; we were asleep before dark on more than one occasion. It would have been nice to have a little fridge, but they want you to rely on their restaurants, so the only food you could keep in your room were nonperishables.

We bought our trail mix, juices and snacks in West Yellowstone before we entered the park, and with the variety of food available at each of the lodge areas, we were working hard to finish it all before we left.

The Yellowstone Caldera is over 40 miles wide, and it’s a long way around from one place to another. Maybe not long in miles, but the traffic is one lane each way and there are many things that can slow traffic down.

The bison are the biggest cause of traffic jams. Sometimes they wander onto the road and cars can’t pass. Too often, people stop to take pictures of them wandering several yards off the road. I actually saw people stop their car in the middle of the road to get out to take a picture. After you’ve been in the park over a day, you will realize the bison are everywhere and there's no need to cause these traffic delays.

Of the things you must see in Yellowstone, the bison will be there wherever you go. The following is my list of places to be sure to visit before you leave the park:

The Lower Falls of the Yellowstone Grand Canyon crashes 308 feet down into the canyon. There are several overlooks along the north rim that are easy to get to, but for those who can make it, the Brink of the Lower Falls overlook is a sensational experience. The roar and pounding of water as wind sprays you and it disappears over the brink creates the feeling that you're following the water down into the depths.

If you’re up for a workout, another good view of The Lower Falls is from Uncle Tom’s Trail on the South Rim. There are 328 steps going three-quarters of the way down to the river. The original trail descended another 200 steps, followed by ropes to bring people to the water’s edge. If you can climb the equivalent of 21 flights of steps, don’t miss this trail.

Surrounding the most famous attraction in the park, Old Faithful area trails are packed with geysers. We spent the entire day walking around and saw six different geysers shoot off (Castle Geyser, left). If we didn’t have dinner reservations, we could have seen two more. Most of the walking area is boardwalk or smooth pavement and several of the geysers have benches, leading to a leisurely stroll along almost five miles of trail.

The 2.1-mile Observation Point loop is up a small hill and a shady walk back to Solitary Geyser. If you have the time and inclination, there are two extended trips you can take to Black Sand Basin and to Biscuit Basin. Both have some visually stunning features.

Norris Geyser Basin is one of the visually striking areas of Yellowstone; however, be aware that it stinks and the acid in the escaping gases is toxic and can choke you. Wear a hoodie that’s thick enough to provide something to breathe into. The wind determines how much the gasses will be a problem, so on a calm day you're less likely to have steam blowing into your face.

There are many thermophile communities creating brown, red, green, rust and yellow colors in the heated water. The upper part of Norris is aptly called Porcelain Basin for the milky smooth and typical blue colors seen in porcelain. Back Basin is much larger and covers about three miles of steaming geysers and bubbling springs.

Yellowstone's Grand Prismatic from the trail.

The Grand Prismatic, located in the Midway Geyser Basin, is another well-known feature of Yellowstone. There's a walkway past it, but it is difficult to see it all so close up and the wind could easily be blowing towards the walkway, totally obstructing the view. The best view is up a steep hill located one mile in on the trail to Fairy Falls as it passes the south side of the feature. There are many fallen trees going up the hill, so it requires a fair amount of agility, but the postcard view of the Grand Prismatic is worth the climb.