The National Parks website provides details of the country's 53 national parks.
There are several great parks in the vicinity of Yellowstone, notably Grand Teton National Park, just south of Yellowstone, featuring jagged granite spires, lakes, moose, bison, wolves, hiking and rock climbing. Neighbouring Montana's highlight is Glacier National Park, with mountain goats, eagles, mule deer, marmots and bears.
The prairie, grassland and forest landscapes of Wind Cave, North Dakota, protect elk, bison and prairie dogs, and the Badlands of South Dakota are home to bighorn sheep, golden eagles, bison, mule deer, pronghorn antelope, large prairie dog colonies and great hiking.
Other parks you might want to consider include: the Great Smoky Mountains, Big Bend, Texas, the Everglades Rocky Mountain and Wichita Mountains National Wildlife Refuge, Oklahoma.
Island hopping
My wife and I are going to be in the Netherlands for a month in July next year and we'd really like to take a short island-hop tour of the Wadden Islands. Could you suggest a possible itinerary (about five days) leaving from Amsterdam en route to Groningen in the north that might include a day or so of not-too-strenuous bike riding and hiking? John Armstrong
The necklace of low-lying Wadden Islands (also known as the Frisian Islands) is made up of Texel, Vlieland, Terschelling, Ameland and Schiermonnikoog. It's perfect for a few days of island-hopping but the islands are hugely popular in summer as the city-bound Dutch escape.
There are plenty of accommodation options but book ahead if you are travelling in July and August. Some ferry links may require advance planning but, in general, island-hopping (or Wad-hopping) shouldn't be a problem.
It's a one-hour train trip from Amsterdam to the port of Dan Helder, where a bus will transfer you to the 20-minute Teso ferry service to Horntje on the island of Texel. Texel's white beaches, lush nature reserves, forests and attractive villages make it a great place to visit for the day or you could spend a little longer to explore by pedal power. De Cocksdorp at the northern end of the island is the ferry departure point for the car-free island of Vlieland.
Vlieland is the most isolated of the islands, with much of its western end at the mercy of sand and sea. There are plenty of cycling and hiking opportunities. For nature hikes and bird-watching walks, consult the tourist office in the island's town, Oost-Vlieland.
Terschelling is the largest and most visited of the Frisian Islands. Its picturesque villages are strung out along the southern edge of the island while its northern coast is all sand dunes and white beaches. For information on ferries, visit rederij-doeksen.nl.
Schiermonnikoog is the smallest and most serene island. This national park is the perfect spot to hire a bike, pack a picnic and head into the great outdoors.
Wagenborg runs ferries between Schiermonnikoog and Lauwersoog in Groningen province, where a bus connection will take you on to Groningen.
