Stay and play in the U.S. of A., affordably

WITH international travel affected by world tensions, many Americans are turning to domestic vacations. Here’s a brief rundown on purchases they might consider making before traveling or actual trips they might book.

* National parks: Fifty dollars is a small price to pay for a year’s access to our country’s finest parklands. Annual admission to Yosemite, Yellowstone, the Grand Canyon and dozens more is $50 when you purchase a National Parks Pass, (888) 467-2757, www.nationalparks.org, which includes entrance for a vehicle full of people. If you’re 62 or older, $10 buys a Golden Age Passport, allowing for lifetime entrance to national parks for passholders and the passengers in their vehicle. Combined with lodging specials from Xanterra (which handles reservations for many parks), www.xanterra.com, you have an affordable combination.

* Park volunteers: How about spending $80 for a healthy, fun volunteer vacation in our parklands? Fixing hiking trails isn’t a priority nowadays, given the beleaguered budgets of many parks. But picking up the slack are volunteer work groups assembled by the American Hiking Society, (301) 565-6704, www.americanhiking.org, of Silver Spring, Md. It offers 100 trips a year for such badly needed efforts as reconstructing a hillside trail in an Alaskan rain forest, replacing a shed’s roof in Tennessee’s Great Smoky Mountains or rerouting a wildlife passage in New Mexico’s national forest.

Projects last from a few days to two weeks, but after your transportation costs are met, the charge is $80 for AHS members, $20 more for nonmembers. Lodging (cabins or campsites) and often meals are included.

* Bike trips: An equally cheap $10 to $25 a day covers camping fees and luggage-carrying wagons on organized bike trips in the United States. Dozens of nonprofit cycling clubs organize budget-friendly bike trips, and pedaling enthusiasts of all ages are invited. At the National Bicycle Tour Directors Assn. Web site, www.nbtda.com, you’ll find information on group cycling trips. Fees cover camping, luggage transportation, medical and mechanical support, and usually food and hot showers along the route.

* Bargain trips: Trip prices have never been as cheap as they now are. For instance, $499 covers airfare from the West Coast and seven nights in Hawaii. California-based SunTrips, (800) 786-8747, www.suntrips.com, offers a wallet-friendly week in Waikiki, priced at $499 in May and $559 to $689 in June and July, including seven nights’ hotel, airport transfers and round-trip airfare from Oakland.

Guests stay at decent properties, such as the 439-room Hawaiian Monarch, a short walk from the beach and its hundreds of shops and restaurants. Single supplement: $150.