Tour of the Oisans: The GR54. Kev Reynolds

centred on La Bérarde at the head of the Vallée du Vénéon in the centre of the range, but it took another 60 years before the Parc National was fully established. It now covers an area of some 91,800ha, with an outer protected zone almost doubling its size to 180,000ha. The park has scores of peaks reaching over 3000m, and in the 4102m Barre des Écrin the highest summit in France outside the Mont Blanc group.

      Despite global warming the region retains a surprising number of glaciers, the southernmost ice sheets of any size in the Alpine range (albeit glaciers that are shrinking at an alarming rate). And it is largely due to the powerful rivers and waterfalls flowing from them that the deep valleys and ravines have been scoured.

      The main, central core of the Parc National is contained south of the Vallée de la Romanche, and west of the Vallées de la Guisane and Durance. Its southern and western boundaries are convoluted ones, squiggling along and round the flanks of valleys to avoid road penetration and the cableways of ski resorts, always seeking to protect the most dramatic and spectacular mountains. All the highest summits and most of the glaciers are found within the park, and on six of the 10 stages of the Tour of the Oisans the route passes through this central core of Parc National territory. There are, of course, rules that govern use of the park:

       Dogs are not allowed, even on a lead. Respect wildlife and livestock.

       Do not pick or take samples of plants, rocks, fossils or animals.

       Firearms are banned, and all wildlife is protected within the national park.

       Leave no litter. Keep the countryside clean.

       Light no fires.

       Make no unnecessary noise.

       Off-site camping is restricted to an overnight pitch between 7pm and 9am, at least one hour's walk from a road or park boundary.

       Motor vehicles and bicycles are allowed only on authorised roads.

Alpine Flowers and Wildlife

      The vast difference in elevation between valley bed and mountain summit, ranging from 800m to 4000m, coupled with oceanic influences in the north and west, and those of the Mediterranean from the south, are part responsible for the diverse flora of the Oisans region. The fact that crystalline and metamorphic rocks (granite and gneiss) dominate in the north and west, and sedimentary rocks such as limestone, schist and clay are found in the south and east, also plays a major part in the region's rich diversity. According to national park literature some 1800 species (representing half of all French flora) have been identified, 800 of which are protected by law, while around 40 species are considered either rare or endangered, and 35 noted for being endemic to the area.

      Facing page (clockwise from top left): Alpine anemone (Pulsatilla alpina); St Bruno's lily (Paradisea liliastrum); poppies in Les Gauchoirs on Stage 10; the stemless carline thistle; the great yellow gentian (Gentiana lutea); alpenroses add a vibrant splash of colour to summer hillside.

      On the Col du Lautaret at 2058m the University of Grenoble has a Jardin Alpin which has a good representation of local plants, but since this col is not included in the Tour of the Oisans it might be worth mentioning a few of the alpine flowers that may be seen along the way. In the early summer, or in higher regions where the snow is melting, the tassle-headed alpine snowbell, Soldanella alpina, is one of the first to exploit the damp meadows, and is closely followed by the spring anemone, Pulsatilla vernalis and its almost purple-flowering cousin P. montana. Various gentians are seen in summer, with the great yellow variety (Gentiana lutea) growing to a metre or more in height, its clusters of flowers arranged at intervals down the stem, appearing towards the end of summer.

      Boggy regions are advertised by mattresses of cottongrass. The prized edelweiss (Leontopodium alpinum) can sometimes be found in limestone areas, while the beautiful dwarf rhododendron, the alpenrose, R. ferrugineum, covers large sections of open hillside up to 3000m and flowers with a blazing hue from late June to August. Extravagant stands of the feathery asphodel, Asphodelus albus, may be found on meadows and rocky slopes between 900m and 2400m, along with the pure white St Bruno's lily, Paradisea liliastrum, to create what may appear from a distance as a carpet of snow.

      Mosses, ferns and lichens add to the variety but there are, of course, many hundreds more, and anyone wishing to learn about the flora of the Alps will find several useful field guides in the bookshops of Bourg d'Oisans.