Wait, are you sure you were reading contour lines wrong, or maybe just using a map that wasn't detailed enough? I mean, the contour lines do show elevation, but they also tell you how steep something is based on how close they are together. Like, if they're super tight, that's a steep climb, and if they're spread out, it's flatter. I feel like the trick is more about paying attention to the trail itself and using the map to confirm where you are, not just the lines. For Mount Whitney, the turnoff for Trail Camp should be pretty obvious from the trail, it's like a big switchback area before the final climb. Maybe you were just focused on the elevation gain and missed the actual trail markers?