It's about as long as Hadrian's Wall.
(a.k.a. Roman Wall, a.k.a. The Wall, a.k.a. Vallo di Adriano, a.k.a. Vallum Aelium, a.k.a. Severus' Wall) (from North Tyneside, Tyne and Wear, England, United Kingdom to Cumbria, North West England, United Kingdom)
It's about one-and-one-tenth times as long as The 405.
In other words, 75 miles is 1.0357 times the length of The 405, and the length of The 405 is 0.96553 times that amount.(a.k.a. I-405, Interstate 405, San DIego Freeway) (Southern California)
It's about one-and-one-tenth times as long as The English Channel.
In other words, 75 miles is 1.13 times the length of The English Channel, and the length of The English Channel is 0.885 times that amount.(average width between Isle of Ushant and The Walde Lighthouse) (La Manche, Ärmelkanal, Mor Breizh, Mor Bretannek) (a.k.a. The Channel)
It's about one-and-two-fifths times as long as The Panama Canal.
In other words, the length of The Panama Canal is 0.71 times 75 miles.(Canal de Panamá) (Panama)
Connecting the Atlantic and Pacific Oceans across the Isthmus of Panama, the Canal measures 55 miles in length. Ships passing through the Canal are raised (and then lowered) 0.016 miles above sea level through the lock-and-dam system.
It's about one-fourth as long as The Grand Canyon.
In other words, 75 miles is 0.271 times the length of The Grand Canyon, and the length of The Grand Canyon is 3.69 times that amount.(a.k.a. Gran Cañón) (Arizona) (Colorado River miles measure)
The Grand Canyon has a total length of 277 miles along the course of the Colorado River at its bottom. Having opened in early 2007, the Grand Canyon Skywalk allows tourists to stand on a horseshoe-shaped glass walkway 0.684 miles above the floor of Granite Gorge.
It's about four-and-a-half times as tall as Olympus Mons.
In other words, the height of Olympus Mons is 0.22 times 75 miles.(a.k.a. Mount Olympus) (Mars)
It's about one-tenth as long as The Rhine.
In other words, 75 miles is 0.0914 times the length of The Rhine, and the length of The Rhine is 10.9 times that amount.(a.k.a. Rhein, a.k.a. Rijn, a.k.a. Rhin, a.k.a. Rain, a.k.a. Reno, a.k.a. Rhenus, a.k.a. Ryn) (from near Reichenau, Switzerland through Hoek van Holland, Rotterdam, Netherlands)