Watch the weather. March can come in like a lion, as the saying goes, and you’re crossing the Sierras and Rockies. Even with AWD, some bad storms will shut the interstates down. And that’s not just over the mountain passes — snow and ice can be an obstacle in the plains states during March. Just watch the weather, and be prepared to head south to I-40. Or, consider doing the southern route on the way there, then the northern route on the way back. Anyway, watch the weather. I got caught in the April, 1983 ice and snowstorm while crossing the country eastward on I-80. Not fun, and that was April.
A rule of thumb to perhaps consider is to plan more time for (or focus on) the places farther from where you live.
Among your route options, I have driven I-80, I-70, I-40 and I-10 across the country, and here are my recommendations.
Instead of I-80, drive US-50 through Nevada until it hits I-15 in Utah, and then pick up I-70 the rest of the way. US-50 through Nevada is a very good road, and you can drive 70+ MPH on most of it. I don’t recall its speed limit. It connects far-spaced towns, which you’ll have to slow down for. US-50 is unique for its “Loneliest Road” moniker (by Life magazine in 1986, although these days it’s well-traveled), and it is more scenic than I-80. In Colorado, I-70 takes you through beautiful Glenwood Canyon, and then past Vail and up and over the Eisenhower/Johnson Tunnels. At over 11,100 feet the tunnel pair is among the highest vehicular tunnels in the world. Hopefully it’ll be warming up and you’ll get the springtime wildflowers, and Glenwood Cyn will be even more pretty. I-70 was the first interstate project in the country, and its section through Glenwood Canyon was one of the last sections, of the original interstate plan, to be completed.
Places to see: a must-see is the Gateway Arch in St. Louis, including its ground floor Museum of Westward Expansion. In St. Louis, get some good BBQ at Pappy’s Smokehouse on Olive St. If you arrive by lunch time try the burnt ends, but they usually run out of that by early afternoon. There’s also the Gobble Stop Smokehouse a little west of the city, on Olive Blvd. at Fee Fee Rd. It’s BBQ turkey, and if you go, get the ribs. Both places are very casual, but eith great food. If you’re a fan of US History, there are two Presidential Museums along this route, Eisenhower’s in Abilene KS and Truman’s in Independence MO, and both are good.
Along the southern route, joint must-sees are Monument Valley and the Grand Canyon. From Albuquerque, swing northwest up to Farmington and Shiprock (and do swing over to Shiprock, the landmark) to Monument Valley on US-163. After Monument Valley, go via Tuba City and where Hwy 160 ends at Hwy 89 there’s a unique sign for the Grand Canyon: North Rim - turn right, and South Rim - turn left. The North Rim will be a longer trip but has far fewer visitors. Along this South Rim approach, Highway 64 offers several nice viewpoints with fewer people, and it avoids the main crowded stop at Grand Canyon Village.
Further east, in Arkansas, Clinton’s Presidential Library is in Little Rock. I haven’t been to that one yet, but have been to 7 of the 13 of them and they are quite good, so I expect Clinton’s to be good.
On your final approach to home take Highway 395 from the south and enjoy the breathtaking eastern side of the Sierra Nevada, and Mono Lake. These are right in your backyard but is so much nicer than I-5.
I’m sure there are other must-sees but of the ones I’ve experienced, these are them. Consider XM radio, too, for listening on such a long road trip.
Enjoy the trip, and let us know what you end up doing.