The Arctic? No, too obvious (the poles' magnetic field screwing up telemetry), and Megatron already ended up there. The Sahara? Nice (anything could be found there), but that's been taken by the original Primes. Mount Saint Helens? Despire the off-putting name, it'd probably work both as a homage AND an actual location (the 1980s eruption could be taken as TF-related).