Hi, so I am strongly considering attending Lewis and Clarke law school.
The school has the best animal law program in the US and a renowned environmental law program (which is why I’m interested in the school) however based on my research the school’s overall rankings do not look too great.
What are the pros and cons of attending a law school that has a very good program for the field of law I want to go into but who’s overall ranking is not that high?
there is no such thing as having a very good program in xx field and being low ranked.
The former is just marketing hype and the latter determines your chances of getting a job.
Unless you can attend for free/near free, it would be a big mistake. Mean salary of Lewis & Clark grads is $50k, clearly not enough income to pay off loans.
I guess I’ll disagree with @bluebayou’s absolute statement that “there is no such thing as having a very good program in xx field and being low ranked” the way I disagree with most such absolute statements (unless you’re talking about the law of gravity and such), but you need to be very careful in your choice of school. I’m probably not as rigid about rankings as a lot of folks. I work for a state supreme court, and I had a Lewis & Clark grad as a clerk on my staff the last two years. She did an excellent job and moved over to a different staff on the court when her clerkship ended. Not all employers are that open-minded, as I guess bluebayou’s comment might suggest. It sounds as though you want to go into environmental law rather than animal rights law, and there are many higher rated schools that can fit that bill, so I would agree with bluebayou that Lewis & Clark might not be the best choice unless the dollars work to your benefit.
ok, I’ll play.
Vermont is considered #1 (however defined) in Enviro Law, with Lewis and Clark #2. Yet, Harvard Law is a lowly #11. Does anyone really believe that attending VT or L&C is a smarter legal play than HLS (or other T14)? Heck Yale aint’ even on the first page. Guess it is off the table? 
https://www.usnews.com/best-graduate-schools/top-law-schools/environmental-law-rankings
Ignore the field-specific rankings. Period. If you’re looking at a law school’s ranking, look at the overall (i.e., US News or other overall) ranking.
Where do you want to practice law? If you are looking to stay in Oregon or the PNW, your chances of getting a job out of L&C are better than if you want to go to LA or DC or NYC.
You should look up Law School Transparency – they have great reports with stats on schools. Only about half of Lewis and Clark grads get jobs as lawyers (almost all in Oregon). That seems like a risky bet to me. School specialities or programs can be something to consider when you’re comparing schools with similar employment outcomes. But you shouldn’t expect that your outcome will be the outlier.