The normal Māori method of travel was on foot. The North Island had an extensive network of single lane one metre wide tracks that traversed beaches, plains, valleys and mountain passes. Some of these tracks were used by many and were considered neutral territory. Missionaries who travelled with Māori guides found that at river crossings canoes were left for the use of any traveller. Between 1840 and 1850 numbers of explorers, artists, government officials including Governor Grey travelled inland with the aid of Māori guides. The guides carried heavy loads and would carry Europeans across creeks. Crossing swamps was common. Although they carried some food they relied on purchasing basic foodstuffs such as potatoes or native pigeons from Māori settlements. The most popular payment was in tobacco which was in great demand. In more remote areas travellers sometimes found Māori living by themselves and growing a few potatoes.