At the end of the ride right near the parking lot where his car was there's this big hill, monstrous in my opinion

It's about 3/10 of a mile long and moderately steep. I don't know the grade of the hill unfortunately. He's been egging me on to try going up it for a few weeks now and I've been declining until last night. I figured why not it can only make me stronger, right? and it will help me get ready for a metric century we're planning to do in September in Lancaster, PA (I just hope their idea of "rolling hills" as it was described are A LOT smaller than this thing I attempted last night!
