I’m a lifelong hiker, so when I moved to Oregon from Arizona in 1983, I was dying to explore my new state’s hiking trails. The first thing I needed was a reliable outlet for USGS topographical maps, and I soon found it in Captain’s Nautical Supply (I was living in Portland at the time, and Captain’s Nautical was the go-to place in those days).

Those maps kept me satisfied for a while as I began to tramp the trails around Mount Hood, the Columbia Gorge and the Central Cascades. But eventually, I wanted to branch out and hike farther afield.

One day I was browsing the aisles at Powell’s Books (right across the street from Captain’s Nautical) and I stumbled across one of William L. Sullivan’s hiking guidebooks. Suddenly, the whole state opened up before me. Now, instead of poring over maps and trying to imagine what the terrain might be like, I had the inside scoop from someone who had been there before.

Bill Sullivan has been my Oregon adventure partner from that day forward.

If you’re not familiar, Sullivan has written an absolutely indispensable series of “100 Hikes” trail guides covering the entire state, with individual volumes for Northwest Oregon, the Central Cascades, the Oregon coast, Southern Oregon and Eastern Oregon.

The trail descriptions average about two pages, telling you everything you need to know. All the basics are covered, of course — driving directions to the trailhead, a description of the route (along with the most popular or interesting variations), mileage and elevation data, the best time of year to go, what permits are required and so on.

But these books give you so much more — notes on campsites and water sources, when to look for huckleberries and watch out for mosquitoes, tips on interesting flora and fauna to watch for, and fascinating descriptions of local history and geology, all illustrated with the author’s handsome photos and charming hand-drawn maps.

Sullivan regularly updates the guides to keep them current, and he’s written a number of other books as well — among my favorites are “Listening for Coyote,” an account of his epic quest to traverse all of Oregon’s wilderness areas on foot, and the morbidly fascinating “Oregon’s Greatest Natural Disasters.”

If you’re looking for a new trail to hike, you’ll find it in one of Sullivan’s guidebooks — along with all the intel you need to get the most from your journey.