Tanzania closed its [M 002 / border] with Kenya in 1977 after years of accusing Kenya of unfairly profiting from Tanzania's wildlife while leaving little revenue in Tanzania. Once the border closed, Kenya developed tourism in the Mara. By the time the border reopened in 1983, the Mara was nearly as famous for its diversity of wild animals as the Serengeti.
Since most of the safari traffic originated in Kenya, tourism all but dried up in the Serengeti. Without the revenue from tourism, much of the infrastructure such as roads and lodging facilities fell into disrepair. Poaching in the park increased dramatically because of the lack of funds for law enforcement and the absence of tourists. When the border reopened, Tanzania began charging higher entrance fees for safaris originating in Kenya and developed safari tourism originating in Tanzania.
