Trek also has a couple of good off road touring bikes. For Flat Bar the 1120 is a great platform, The 1120 is designed more for single track and gravel roads. It has some interesting racks. Fully loaded or stripped down its a very noble and capable bike.
For the Drop Bar Gravel/Adventure Touring the 520 Grando is hard to beat (I’m a little biased as I own one). The 520 hit the show room floors in 1983 and continues production through 2023 MY. Over the years the frame evolved as the biking industry itself evolved. Pre 1999 frames aren’t very desirable for gravel conversions because the width of the fork and rear drop outs can’t fit a wider gravel tire. In 2020 the 520 frame made a huge change allowing tires up to a maximum of 29x2.0” without fenders. The Grando comes with 700c40mm GR1 Tires that run decent on the pavement and offer excellent grip in deep gravel while offering total control on the single tracks. The Shimano GRX 10 speed rear cassette combined by the 2 speed ProWheel 42/28 chain ring offers a great diversity of gears for both the street and the trails with an awesome low range for those fully loaded climbs.
Right out of the box, both bikes mentioned are fully capable with lots of aftermarket support for upgrades later on.