Let's discuss the distances stated on most maps. Go to a travel information building, order a trail map, or even viewing a trail map on a website, there's somewhere on that map that will tell you the distances. As an example, "Green trail loop is 3.5 miles long.", or "Red trail is 11 miles long.". The reality is you should add at least .5 to 1 miles to that declared distance.
Why?
Because most trail maps have not been modified or updated in decades, and were not created to exact distances of the trails to begin with. They also don't include additions to distances for declines or inclines (going up or down hills). Or know if there's a spot on the trail that's blocked by water or some other object you have to go around.
I will usually add at least .5 miles to any trail I have not been on before. So if the trail map says it's .75 miles to Dirty Undy Falls, I'll plan on it being 1.25 miles at minimum.
Here's a great example of this:
ears back my wife and I decided to hike a trail in the ADKs that was stated just under 2 miles. Adding .5 miles to that I estimated our hike should take about 2 hours. At the trail head they did not mention they were re-working this trail. Over all we ended up crawling under downed trees through water, climbing over other downed trees, going around other obstacles, and even losing the trail. Yes, the trail markers stopped and there literally was no trail. Being in the process of remodeling that part of the trail they had removed the markers, and the old trail was gone and the new trail led to an abrupt stop in the middle of the woods. We went back to the last marker, and I had my wife sit tight while I went ahead to try and locate the trail. I knew the point we had to go to get back to the trail head, and took a compass reading where I left my wife. The plan was if I did not find the trail we would turn back. I zig zagged the woods for about 800 yards before finding the trail again. But was it the right trail? I went back and got my wife and we went back to the point of the trail I found. I took another compass reading. Then I looked for trail markers. I saw none! I told her to sit tight and I'd scout up the trail a little. I went about 100 yards and looked back. Well look at that! Trail markers! They marked the trail for one direction and not the other. I called for her to come up to me. I repeated this, going forward a few trail markers and then having her come up until we got to a building and an old woods road. I eyed the compass and told her the trail head should be this way, and pointed up the road. Once again, I told het to sit tight and I'd scout ahead. I got up over a little knoll and and could see something shiny about 1000 yards down the road. I walked another couple hundred yards and realized, with relief, it was the trail head and the shine I picked up was our car windows. I called for my wife who came up and met me. Then we headed to the trail head and back to the vehicle.
The one sure saving grace was the river. The intention of this hike was to go back into a waterfall on a river. So having that river was the reason I did not panic, thought I was concerned. I knew the river went under a bridge about 3 miles outside of the nearest town. So, if we had had to, we could have followed the river out the the bridge then followed to road back to the side road the original trail head was on.
What should have been a 2 mile hike, marked as easy, and taking maybe 2.5 hours, was really about a 5-6 mile hike that took about 4.5 hours, and loosing the trail at one point along the way.
So, plan your hiking accordingly, and always add some extra distance and time to complete your goal.