CHILTERN HILLS, or THE CHILTERNS  , a range of

chalk hills in England, extending through part of Oxfordshire, Buckinghamshire and Bedfordshire . Running from S.W. to N.E., they form a well-marked escarpment north-westward, while the south-eastern slope is long . The name of Chilterns is applied to the hills between the Thames in the neighbourhood of Goring161 and the headwaters of its tributary the Lea between Dunstable and Hitchin, the crest line between these points being about 55 M. in length . But these hills are part of a larger chalk system, continuing the line of the White Horse Hills from Berkshire, and themselves continued eastward by the East Anglian ridge . The greatest elevation of the Chilterns is found in the centre from Watlington to Tring, where heights from 8oc o 85o ft. are frequent . Westward towards the Thames gap the elevation falls away but little, but eastward the East Anglian ridge does not often exceed 500 ft., though it continues the northward escarpment across Hertfordshire . There are several passes through the Chilterns, followed by main roads and railways converging on London, which lies in the basin of which these hills form part of the northern rim . The most remarkable passes are those near Tring, Wendover and Prince's Risborough, the floors of which are occupied by the gravels of former rivers . The Chilterns were formerly covered with a forest of beech, and there is still a local supply of this wood for the manufacture of chairs and other articles in the neighbourhood of Wycombe .