Imagine walking along the trail at Interstate State Park, on the St. Croix River in Taylors Falls, Minn. You peer into one of the strange glacial features known as a pothole. Was this perfectly cylindrical hole cut deep into rock made by aliens, you wonder?

Then a friendly voice comes over your earbuds to offer the real explanation. As the last ice age ended, huge glacial rivers gushed over this land. When water met jagged rocks, whirlpools formed -- including swirling silt and rocks -- and eventually wore away the rock below, leaving smooth, round holes. Alien-like, but totally natural.

Interstate is among the first of our state parks to offer a podcast with insights into geology and wildlife. Visitors can download the goods from the state park website or listen in on an MP3 unit available at park.

Technology can distract us from visiting state parks -- who needs a hike when we can play a game of Wii tennis -- or worse, make a walk in the woods seem dull. Fortunately, Department of Natural Resources officials have hit on a way to make technology work for them.

Not that the digital world has always been kind. A new online reservation system for lodging and camp sites famously crashed at its March 1 launch due to pent-up demand; it is now functioning and, beginning Monday, you can book up to a year in advance.

Armed with a podcast or two, there should be plenty of places we want to spend the night. A growing number of parks have a podcast in the works. Some are posted at the DNR podcast site: www.startribune.com/a1166. Others are posted at the specific park's website.

Send your questions or tips to travel editor Kerri Westenberg at travel@startribune.com, and follow her on twitter @kerriwestenberg.