 Carnarvon , at the mouth of the Gascoyne River , is the only large town between Geraldton and Karratha , and is an oasis within an arid region . East of the town , the landscape near the river features banana and other horticultural plantations , while the vegetation in the surrounding region is primarily shrublands . The highway skirts east of Carnarvon , and crosses the Gascoyne River nine kilometres ( 5 @.@ 6 mi ) north @-@ east of Robinson Street , the main road into the town . 
