Check out weedalert.com. Super website.
Also, much wildlife has instinctively and intuitively learned what to eat and what not to eat! Otherwise their species' would be extinct...or heading that way.
That is why we can study deer, rabbit, etc. resistant plants - they have learned not to eat them for whatever reason.
hortster

Check out your state/county noxious weed control board for identification in your area. I'm going to assume 'northwest' means PNW(that's what it means to me)...

Here is a link that might be useful: WSNWCB

Remember a noxious weed may be on the list only for a specific area. MO had a plant grape hyacynth on their list because they were trying to eradicate it in one prairie location in the state. So if you find a plant double check with your local board to see if the noxious classification is for your particular area.

I can ususally find a picture of what I want to identify by going to Google Images and just keying in ~ Nevada weeds ~.

Now admittedly all the plants in Nevada probably don't amount as many different kinds as some of you have on your back lot but nevertheless and image search on your state and weeds might work. There really are a lot of pictures out there.