The doldrum in foreign visitors to the United States this summer has significantly slowed the tourism industry’s recovery, and some regions have been feeling the effect more than others, especially at national parks in the West.

Consequently, opportunity has been created for more Americans to book trips to the Grand Canyon or Yosemite national parks on short notice. Some have been able to snag discounted rooms at park lodgings.

But the dearth of international travelers has the tourism industry worried. Spending by foreigners has been soft since Sept. 11, and this week industry leaders will launch lobbying efforts to get government help in trying to shore up the $100 billion international travel market.

Leaders of the nation’s $546 billion tourism industry plan to ask Congress this fall to create a national tourism agency to market the United States to international travelers. The group would allow individual states and destinations to compete in international markets they wouldn’t normally be able to reach, said William Norman, president of the Travel Industry Assn.

For national park officials looking at dwindling visitor numbers in what is usually the busiest month of the year, such efforts are particularly timely. Many admit they underestimated how the drop in foreign tourists who account for at least 40 percent of the Grand Canyon’s total visitors, for example would affect the summer season, banking on a much-anticipated increase in drive-in traffic from nearby regions to cover any shortfall.

Trips by car are up between 7 percent and 10 percent at the most popular Western parks, and campsites still have waiting lists 30 names long. But vacancies at lodges and hotels remain easy to find, as cancellations by international groups and tour operators opened up blocks of coveted rooms. At the Grand Canyon, international tour bus arrivals are down 35 percent so far this summer.

In 2000, international visitors spent $103 billion in the United States. Last year, spending by foreign visitors dropped to $91.1 billion, a number that is expected to rise slightly to $94 billion in 2002.