Complex sentence: Officially, the removal was because of visitors'environmental impact, but pressure from locals unhappy with the increased traffic may have contributed, and a letter by the Mojave National Preserve's superintendent mentions confronting Pacific Bell with some long-forgotten easement fees.
Split into simpler sentences: Officially, the removal was done to halt the environmental impact of visitors, though pressure from locals unhappy with the increased traffic may have contributed. Additionally, a letter written by the then-superintendent of the Mojave National Preserve mentions confronting Pacific Bell with some long-forgotten easement fees.