For most of the Carnegie team's time at Uaxactun, communication with the outside world was via a four-day mule convoy to El Cayo, British Honduras. Towards the end of the time an airstrip was opened. Flights to Uaxactun continued and a small village grew there, as it became a center for gathering of chicle sap from the Peten jungle. In 1940 A. L. Smith and Ed Shook of the Carnegie project returned to make some additional excavations. In the late 1970s a rough road was opened, connecting Uaxactun to Tikal and thence to Flores, Guatemala. Air flights were discontinued. In 1984 the road was much improved. Shook returned again in 1974 to oversee consolidation and restoration of some architecture excavated earlier. In 1982 Guatemala's "Tikal National Park" was expanded to include the ruins of Uaxactun within its protected area. In 1990 the Maya Biosphere Reserve (MBR) was created, including Uaxactun as a part of the reserve's Multiple Use Zone.