USGS topo map questions

[caveman]

 

 
16.  What is the feature where the black dot is (arrow pointing to)?

[Ljohnsaw]

A saddle or pass between the peaks.

[rusticretreater]

A gap, a pass or a Col.

[caveman]

Answer to #16 was saddle.


17.  What is the elevation of the point A?
        18.  What direction does the perennial stream shown in section 19 flow?

[dogone]

   I remember the days before gps. On the Beaufort sea we precision navigated with loran or shoran. I believe there was also a decca system. In winter we had supply planes navigate with dead reckoning and celestial compass. They would find us on the arctic ice over 250 miles from their base. And land in the dark.
   Later in life I was a bush pilot. Really liked map reading and finding some obscure point .
    Now all pilots just punch in coordinates and follow the track.

[Andries]

hey, @dogone! Another glaciated Canadian that spent their working life North of 60.
Good to meet you, from a guy that spent most of 38 years doing Arctic marine surveys.
Were you with Borek Air?
Kyle: 130 elevation and N0rth?

[Ljohnsaw]

17.  North
18. 130 feet

[dogone]

hey, @dogone! Another glaciated Canadian that spent their working life North of 60.
Good to meet you, from a guy that spent most of 38 years doing Arctic marine surveys.
Were you with Borek Air?
Kyle: 130 elevation and N0rth?

Spent 70s doing land and sea seismic in north. Marine seismic out of Tuktoyuktuk and land in delta. Two winters off Ellef Ringness Island. We had Borek flying for us out of Resolute Bay. Did my flying in n. Sask. 
    Point of interest: worked in Sinai desert in Egypt. Right beside Gaza.

[SwampDonkey]

We also call that a divide up here, drainage can run one way to one brook or the other way to another. Looks like two major gullyes there.

[caveman]

Andries and IJohnsaw were spot on.  I enjoy reading about the experiences of the FF members.  

[caveman]

 

 
#19.  How much elevation change is between .A and .B?
#20.  What do the light green circles that are shown on much of this section of the map represent?         

[Magicman]

Looks like A is 230' and B is 250'.  Foliage.

[Ljohnsaw]

Hmm, looking at the lines to the left of A along the road, it looks to me like A is lower than the 200 line. I put it at 140'? Not sure what those hash marks mean on the lines.

B could either be 100 or 300. Since there isn't a water feature indicated, thinking 300. So the total elevation change is 160'?

20. An orchard?

[Magicman]

100' elevation is in the lower center so A & B should be higher than 200'.  I see them as the higher points on the map.

I actually did not see the green circles until I enlarged the map so...??

[beenthere]

A is 140' and B is 300' the way I am seeing it.

[NE Woodburner]

#19: Question is elevation change between A and B and I see A at 170' and B at 250' so 80' elevation change?
#20: Green dots represent vegetation/wooded areas?

[caveman]

#19 is .A=170', .B=250' with a difference of 80'.  Woodburner got it.  
#20 answer is indeed an orchard. IJohnsaw nailed it.  
 
Most of the time in my neck of the woods, an orchard is a citrus grove (which really is not a grove), or at least it used to be.  A few farmers tried peaches, but fruit flies, not enough cool nights to make them sweet some years plus our market is generally over when others come in made them a tough crop to grow for profit.  Often when walking in the woods in central Florida I've come across hammocks with sour orange trees growing in them.  I suspect these were areas Indians used to live on or at least frequent.  I've eaten some of the fruit from these trees over the years but never tasted any that weren't incredibly sour.  I do not recall ever seeing any of these trees with symptoms of Citrus Greening (the disease that has devastated the citrus industry in Fla.)  Maybe the Asian Citrus Psyllid, the vector of greening, has not found them yet.

We had the county FFA citrus judging contest yesterday in Frostproof, Fl.  Our team did well.  They still have some citrus groves down there.  Our county is roughly 1800 mi2 and Frostproof is a haul from my place.

[SwampDonkey]

My grandfather had his very first hunting camp back in the 20's on one side of a divide. The brook he was on flows into the Saint John River. You could walk a ways in another direction and hit the head of another brook which flowed into the Tobique River. In fact he followed an old road from town out there, a brook flowed along to town for their water source, town was on the Saint John R. You'd hit the head of the brook and be heading down into another brook that went into the Tobique down to the left, but that went out to the divide to the right and up hill, then you dipped down again in to where the camp was on that next brook, which eventually hit the Saint John. And maybe a couple miles east of that road near that divide and the land divided again and water goes to the Miramachi River. Nothing is ever a straight line unless like yours, one gully falling away from the other. It probably looks like cotton clouds the way the contours go. :D There's steep climbing on those hills for sure. Travelling the gullies and creeks was a lot less steep than up over. :D It's nowhere near that hilly around my place, near flat, although I always said I was on a side hill, but easy side hill. Everything flows down hill from the front door. :D

[peakbagger]

Up in the mountains of NH, we have some topo map situations that are probably not in Florida. Situation one is when the contours lines are touching each other. That means cliffs and in some cases, overhanging cliffs. Second situation is white areas in combination with contour lines nearly touching, that means bare rock with little or no vegetation. Generally place to avoid when bushwhacking cross country although some folks seek them out as they frequently have great views from up at the top. 

[caveman]

I have an old book of topo maps somewhere.  I recall seeing some with the lines touching or nearly touching each other and the contour interval being 100'.  These maps were not in Florida.  The highest elevation that I know about on peninsular Florida is 312' at Iron Mountain on the Lake Wales Ridge.  It is the site of Bok Tower.   Bok Tower Gardens, surrounding the tower, was designed by Fredrick Law Olmstead.

?#21.  Which is likely the most famous park designed by Fredrick Law Olmstead?  

[Ljohnsaw]

Shot in the dark: either Golden Gate or Central.

[caveman]

#21 answer (IJohnsaw again for the win)- Central Park

[Old Greenhorn]

Enjoying this thread even if I am not participating heavily. I think reading a topo is a basic skill which should be taught in all schools. I've spent many hundreds of hours pouring over maps, laying routes, and learning terrain before I enter into an area. I used to print out custom topos for my scouts and get them to sit down before a trek and look and the map and have a discussion as to what they could expect to find on the path we would follow. I'd also break that map into sections and each morning hand the leader his map for the day to work from. By that time, they knew all the symbols and could read the terrain. When the trail got confusing, we would stop and try to find where we were exactly on the map based on the terrain we could see around us and points we could site for a back azimuth. I sure hoped they learned something. ;D
 Anyway, they have always been fun for me, and a resource I would not want to be without while in the woods. I have not seen the gridlines on out topos that you have on yours and knowing the plot size was never something I had learning up in. SO I learned a little there. I'll have to see if they are putting grids on our maps here now. All my maps are 'old' like me, they don't change much (also like me).

 Funny story and this is before GPS. My Boys had planned a 'spring trek' of about 25 miles or so through our mountains here, some of the nicest hiking trails in the country. Since it was an extended backpacking trip in the shoulder season across a series of peaks, water was a concern, there ain't none up on top to be found except snow melt, which you can't depend on in that season. So in the month prior to the trip I did a series of solo hikes up the cols to various spots along our planned route to cache water jugs. I noted these on the map for them to find as part of the skills application. Well, I was on one of these cache hikes carrying about 60# of water and found a spot and hid it. That day and that trail was almost all ice after I hit a certain elevation and I put on my ice spikes to get up it. On my way down I had just gotten to the large flat rock where I put my spikes on going up, and I took them off. Directly, a group of young men, about 25 y/o were coming up the trail and we chatted. I noted they had some new gear, in fact it all looked new. One fella says "this trail goes up to the top and then where does it go?". 'Well, I said, it ends at the Devil's path Trail, which goes east or west.' "Oh, well which way to the trail shelter?". I explained there was one in either direction. They looked puzzled and were trying to decide which way to go. So I took out my map to show them the distances and other details. As I pulled it out of my shirt pocket, one of the guys says "Oh HEY! LOOK! he has a map, that's pretty cool!" I look at them, stunned. I ask them "It's March, there is Ice everywhere and you guys started out on your hike without a map, or a plan, or even knowing whether to turn east or west at the top? You have all that new gear and you couldn't go an extra $5.00 for the next most valuable thing than water? REALLY?"
 "Oh they said, we have a plan, we just didn't find one of those maps. Probably be handy to have next time." I chuckled "yeah, ya think?"
 I wished them luck and headed on down. Darwinism at work, that.

 Sorry if I crashed the thread, but map reading is a vital skill, so seeing it discussed and practiced here is a valuable thing.

[peakbagger]

 

 They did themselves a favor and covered Table Rock with a contour label. 100 foot primary contour intervals 40 foot secondary. It hangs out over the face of the cliff looking down at the road. It is about 4' wide at its tip, nice place to hang out on a nice day with a shear drop on either side. Quite a ride through the notch in the winter.

[Big_eddy]

And not a bad view of the Balsams resort from the top.