Crater Lake mesmerizes. Some consider it the most beautiful body of water on the planet. It’s 1,953 feet deep and holds the world record for water clarity. Taking a national park service boat trip there makes dreams come true.

Sometimes.

The side-by-side photos below are from two separate vacations, one from late June and one from late July, only four weeks apart. We’ve experienced several great vacations at Crater. And two that were less memorable: one when the park was still snowed in during the summer and another where we failed to research the lake’s boat excursions, which closed two years for renovations.

I hope you get my point. It’s all about planning. And sometimes a little good fortune. But mainly planning. Did I mention planning?

Pick the right time of year to visit national parks

Our national parks are treasures, yet sometimes they don’t feel as majestic as you fight crowds in the visitors centers and parking lots. Arches, Yellowstone, Yosemite, Zion and the Grand Canyon suffer from severe overcrowding during peak summer season and weekends. Only Zion has effectively addressed this pressure by installing a shuttle system and eliminating car traffic to its gorgeous valley.

Some families are locked into summer and school break schedules. When our daughter was younger, we planned several national park vacations to leave on the day after school ended, when tourist numbers hadn’t yet reached the summer surge. We noticed a difference.

Some alpine parks have limited access for 9-10 months, meaning your window of opportunity is small. Snow reduces the summer tourist season at parks like Glacier, Mt. Rainier, Lassen, Canada’s Jasper and Banff, and our Alaskan parks. And hot temps limit places like Death Valley and Saguaro national parks. Scour a park’s website – most publish historic temperature trends and we always study these before making travel decisions. And of course, retirement gives us a lot more flexibility.

Pick the right accommodations

Plenty of travel sites can influence your selection. Your biggest decision should be whether you stay inside the park or elsewhere. We prefer to stay inside the parks, closer to trailheads and sights, minimizing how far we drive each day. For instance, we always try to hotel it inside Glacier and Yosemite. In some parks, this isn’t as strategic of a decision as elsewhere. Zion and Bryce are great examples; there’s convenient lodging just a couple of miles from the main gate. Most park lodging, operated by contracted concessionaires, is okay if you like rustic rooms and average meals.

When we visit Mt. Rainier, we prefer to stay just outside the park and tolerate a daily commute inside. Why? Food and accommodations. The options inside Mt. Rainier have not been to our liking. In addition, try to book early, especially for the park’s lodging, because they’ll fill up fast, often a year in advance.

Consider your travel companions

Pick national parks that suit your family or guests. For instance, if you love beauty but your clan doesn’t like to walk or hike very far, then the Black Hills, Bryce, Arches, and Saguaro could be perfect for your trip. They offer plenty of roadside and turnout views. In contrast, parks like Cascades, Vermilion Cliffs and Kings Canyon require more exploration and feature less eye candy from overlooks.

Choosing the right time of day to explore

People often associate vacations with sleeping in. That approach in many parks guarantees that you’ll be accompanied by a gaggle of 100 to 300 tourists while you’re walking in the great outdoors. We hike early to avoid crowds, beat the heat and see more wildlife. Then, we often rest during the afternoon and head out for an evening walk or drive to absorb the sunset.

I recently counseled a family vacationing to Yellowstone during the height of the summer tourist season. Their accommodations were on the west side of the park, an hour from Old Faithful and Geyser Basin, if you drive early; it’s twice as long once everybody wakes up and fills the roads with cars and buses. My main recommendation? Hit the road at 6 a.m., drive to Old Faithful and experience nature’s serenity. They told me that advice was gold. Instead of a thousand people waiting to watch Old Faithful blow, they shared the experience with a handful. And they saw lots of wildlife during the early drive into the park. Set the alarm early!

Ask a ranger for best hikes without crowds

Some of our all-time favorite hikes happened because we asked a ranger this question: “What’s your favorite hike away from the crowds?” Upon arrival at national parks, we head straight to the visitors center and chat with the staff. Yes, we still hike the more famous, popular and crowded spots, such as Yosemite’s Mist Trail. But one of our best memories in Yosemite is Chilnualna Falls, a place we chose after getting a ranger’s fondest recommendation. And we saw a whopping 10 people! Park staff can also share the most current road and trail conditions, which sometimes change day to day. Mountain lion activity yesterday, washout this morning, killer bees in the canyon area – we’ve heard it all. So, God bless the rangers.

One last bonus tip: savor the parks. If your initial plans include five parks in two weeks, cut the list to three. Slow down, lower your blood pressure and enjoy.