Hoyt Arboretum
More than 1,000 species of plants and trees reside inside the Hoyt Arboretum. How well do you know them all? Odds are, you’ll be something of an expert after tagging along on a tour of the place with Hoyt Arboretum Friends. The group’s popular 90-minute guided nature walks return this weekend. Choose from a 9:00 a.m. outing detailing the arboretum’s collection of conifer trees, or an 11:00 a.m. tour to admire a batch of flowering trees. ($3; All proceeds benefit Hoyt Arboretum)

Love Your River
Pssst. Hey, you got any drugs? Wait… that came out all wrong. Let me start over. Last month I posted about Oregon Environmental Council’s Love Your River campaign in which OEC would be issuing a series of challenges meant to raise awareness about caring for our local watersheds. Well, this month they are back at it. November’s challenge: Keep Your River Off Drugs. It doesn’t get much easier. Simply take your left over or expired medication to an official drug take-back event location. The drug take-back event in our area will be at the Lake Oswego Adult Community Center from 10-2 (503-675-3992; 505 G. Avenue; Lake Oswego). Or if you can’t make it to L.O. this weekend, OEC advises that you throw that stash in the trash, instead of flushing it down the toilet. Otherwise, all those funky meds end up right in our rivers, and weird things start to happen. Like finding male fish with female sex organs. And, well, I’ll just leave it at that. Sign up for the challenge at loveryourriver.org, and you’ll be entered to win a backpack from REI, which, coincidentally, could come in handy for hauling all your expired Advil to the trash.

Oregon Mountain Community
On Saturday, OMC is hosting a Backcountry Expo. Stop on by to check out topnotch touring gear, telemark skis, Nordic skis, snowshoes and more from the likes of Black Diamond, Garmont, and Fischer. Not to be outdone is their used gear sale, at which you can browse the shop’s rental gear from last season. A scuff or two on these boots and skis means some deep discounts and scoring gear that already has built-in character. (503-227-1038; 2975 NE Sandy Blvd; 10-6)