How long would you wait in line for a pass that lasted a lifetime?

Many frustrated bargain hunters waited for hours this week as a looming deadline for a senior pass for the national park system brought them to the only Twin Cities location that still had them available — the Minnesota Valley National Wildlife Refuge — which ran out Tuesday.

The passes, available only to those age 62 and older, who are either U.S. citizens or permanent residents, allow free access to more than 2,000 federal recreation sites. The last day for the senior deal-of-a-lifetime is Aug. 27, when the one-time access charge goes up from $10 to $80. This is the first increase since 1994.

“There’s been incredible demand throughout the nation and locally as people try to get this bargain,” said Sandi Kinzer, visitor service program manager at the wildlife refuge. “We expect the demand to continue because of the deadline.” More than 2,500 passes were sold at its Bloomington visitors center last week, and its final 500 were disbursed on Tuesday in only four hours as seniors flocked to the site.

More passes are on order. The first of the occasional availability is expected after July 26 at the Bloomington visitors center, and they are expected to sell out quickly. Both the website and the recorded phone message for the wildlife refuge reflect current updates.

Kinzer recommends that seniors fill out the mail-in application, which does involve an additional $10 fee for processing. “You’ll be saving $60 rather than $70, but you won’t have to wait in line,” she reminds seniors.

The mail-in application is suggested for those who do not have a pending trip in the next 12 weeks, which is how long these applications are taking to process (and which will likely increase with more applications).

If you have a trip planned before the end of August, she recommends checking out other sites along the way where the pass could be purchased in person (the options go far beyond the well-known major parks to include national forests, monuments and more). For a complete listing of sites, see recreation.gov and call ahead to check availability. Bring along a mail-in application to send, in the event that passes aren’t available along your route.

An online application is also available, though many users have complained on Facebook and elsewhere that is not reliably functional or easy to use.

For updates on the passes at the Minnesota Wildlife Refuge office (3815 American Blvd. E., 952-854-5900, Bloomington, open 9 a.m.-5 p.m. Tue.-Sun.), check the website, or call 952-854-5900.

“Keep in mind you will have the rest of your life to use this pass, even if you don’t have it for an upcoming trip,” Kinzer said.

Find more information at recreation.gov.