USGS topo map questions

[caveman]

I've exhausted most of my local trees for the tree i.d. and after reading through the disorders thread, I have some more of those we can look at, but I thought it might be fun to look at some maps.  I suspect a lot of you relied on these to do your jobs, especially before GPS.

 
 
1.  What is the contour interval on this map?
2.  What is the elevation of C.?
3.  What is the combined acreage of the two black hash marked tracts?
4.  Which vegetation type is at C.?
5.  Which feature is SE of Ford's Arm

This map show up better for me on my computer in my gallery.  It is under State Forestry.

[beenthere]

Can't tell anything from the pic. 
All that info should be in the borders of the map, iirc. 

Do you know the answers to your questions and just seeing if we can give the answers that you know? 

[caveman]

There should be enough info on the parts of the map pictured to answer.  I will try to post a picture of the rest of the map.  It is the Lake Jackson Quadrangle map (Florida).

The area outlined with the red marker in the top picture is section 36.  It has one black hash marked area with the black marker.  I tried to put a picture of the whole map, but the glare and resolution was too bad.  I left the map at work and won't be back there until Thursday.  

[Old Greenhorn]

1: 10'
2: 220'
3: no idea
4: forested
5:  swamp

Never learned computing acreage from a topo. Need a lesson.

[caveman]

Tom, you were right on 1, 4, and 5.  A section is 640 acres.  There are 36 sections in one township.  A section is also one square mile.  Each side of a section is one mile, 5280 feet, or 80 chains.  This will be useful information in the following days.  

[beenthere]

Caveman
It is, until it isn't. Not all sections are created equal, so may lead to a trick question. 

[Dan_Shade]

I'm guessing, is the answer to the second question 205ft?

[Old Greenhorn]

Nah, it's 210'. I fat fingered when I typed in my answer.

[Dan_Shade]

If it's 210, why doesn't it touch the 210 line near it?

I'm either dense or confused... 

[Southside]

Honestly I was surprised to see contour lines on a topo map of Florida.  :D

[Ianab]

Honestly I was surprised to see contour lines on a topo map of Florida.  :D

At ~250ft, it's probably called Mount "something"  :D

[caveman]

I'm not trying to trick anyone.  The best I can tell is that that (C.) is at 200'.  Notice that it is on an index line, which are darker and bold.  With a contour interval of 10', those will always fall on multiples of 10 and 50.  I generally try to get to an elevation spot from two index lines to confirm that I'm selecting the right elevation.  

There is a place on peninsular Florida that is about 310' above sea level.  It is the site of Bok Tower, which was designed by Fredrick Law Olmstead.  He's the same guy who designed Central Park in NY.  The site of Bok Tower is called Iron Mountain, and it is on the Lake Wales Ridge.  It was a great citrus growing site prior to Citrus Greening.  

Southside, most of the maps around my place have contour intervals of 5'.  I lived at an address on the map used above from age 3 until 7.  I had some really good strawberries on my knees from crashing bicycles and skateboards on the newly paved subdivision roads there.  Then we moved to where we live now and with the dirt roads, the skateboarding ended.  I still found ways to get hurt.   

[Old Greenhorn]

AH OK, I mis-understood the question. I pegged 210' where that dot is.
I too was interested to see that interval. I rarely work with a map that has less than a 20' interval around here. In fact, you often sees 6 to 10 of those lines right on top of each other. One of my 'challenge short hikes' I used when training for long backpacking trips was a 1,200' gain in one mile of trail. As I was training I would increase my load while trying to decrease my time, ending up using a 60 pound pack for the climb. I always thought I was doing good for and old guy (I was around 50 at the time) until one day I passed a grandma in her 70's coming down while I was sucking wind going up. I chatted with her for a minute, turns out she does that trail about 4 times a month and has done it for decades.... in house slippers. >:(
My goal had always been to do that trail in the depth of winter when the snow is very heavy and the rest is solid ice. Full crampons, ice axe, etc. 3 times I tried, 3 times I failed halfway up. One time was really not pretty and I sliced up my gaiter one one leg with my crampons from the other foot. If I had got the leg, I might have been in for a rough time. All I'll say is it is not pleasant hurtling back down the hill on your back, head first with your feet point uphill and you can't get your axe into anything because of your speed and the density of the ice.
But I digress, sorry.
Back decades ago I was working as a bike mechanic at the paraolympics (long story) and there was a team of riders from FL that I got friendly with. I asked about their training and where they find hills to work with. He joked and said the highest point in the 5 county area is the landfill at 250'. :D They train for hills on the bridges, which can often exceed 200' ASL and they do them over and over.

[caveman]

Back in 1989 we bicycled across a good bit of Alaska, and we trained for it in Florida. Our longest day was 136 miles, but we also climbed Thompson's Pass, which was around 10,000'.  The only fond memory I have of that day is going downhill for 17 miles heading toward Valdez.  That trip nearly cured me from riding a bike.  

[SwampDonkey]

Never really used topo maps here unless locating road placement. Scale was 1:20,000 on any we had access to. Pretty much used dot grid on aerial photography for areas, 1:12500 scale (all aerial photography in NB forestry). Timber cruising sample locations all off aerials. Other than that, silviculture boundaries were all measured by compass and string box. Then GPS and GIS took over. Had access to property paper maps and microfiche for property size for at least 40 years. Aerial photography been around since the 50's and updated 3-10 years apart generally, but mills often did their own annually. I remember new photos over blocks cut a few months before. Cut blocks were measured post harvest here off aerials, was close enough. Only time I seen measuring string in the woods was for plantation post treatment and thinning pre-treatment. In BC the cut blocks were traversed pre harvest with turn points (falling carners) marked on trees, nylon chain (distance), compass (direction) and clino (for slope changes).

[caveman]

The answers to yesterday's were:
1.  10' contour interval
2.  200' elevation of C.
3.  160 acres combined in the two sections
4.  Forest is green on the map
5.  Swamp or Marsh (there are several types of swamp or marshes)



 
6.  What is the feature that the D arrow is pointing to?

7.  South of the boxed in area, a blue line with three blue dots and more blue lines is seen.   There is another to the west of the boxed in area in the next section over.  What is that feature?

[Texas Ranger]

A marsh and intermediate streams.  I had a problem with the original question when I blew it up to see, it became blurry, old eyes, ya'know.

[clearcut]

The National Wetlands Inventory believes 

D =  This 18.90 acre Freshwater Forested/Shrub Wetland habitat is classified as a PFO6F.

Classification code: PFO6F
System Palustrine (P) : The Palustrine System includes all nontidal wetlands dominated by trees, shrubs, persistent emergents, emergent mosses or lichens, and all such wetlands that occur in tidal areas where salinity due to ocean-derived salts is below 0.5 ppt. It also includes wetlands lacking such vegetation, but with all of the following four characteristics: (1) area less than 8 ha (20 acres); (2) active wave-formed or bedrock shoreline features lacking; (3) water depth in the deepest part of basin less than 2.5 m (8.2 ft) at low water; and (4) salinity due to ocean-derived salts less than 0.5 ppt.
Class Forested (FO) : Characterized by woody vegetation that is 6 m tall or taller.
Subclass Deciduous (6) : A plant community where deciduous trees or shrubs represent more than 50% of the areal coverage of trees and shrubs. The canopy is normally leafless some time during the year.
Water Regime Semipermanently Flooded (F) : Surface water persists throughout the growing season in most years. When surface water is absent, the water table is usually at or very near the land surface.

The blue dot dash symbol representes an intermittent stream. 

The National Map allows you to create a topo, or other maps for anywhere in the US.

[WV Sawmiller]

   Neat topic and visuals. Most of the maps I used were military maps and were typically 50,000:1 IIRC.


  I used to have a drawer full of Camp LeJeune maps I got from the G-2 section and used to have to give map reading classes to fuzzy headed guys in rubber boots with funky BO because when we did a
 big field exercise I'd have to order the Porta-Johns for the exercise. Jacksonville/Onslow County NC area had a high water table and with limited training area we could not dig catholes or slit trenches on that scale so we (I) had to rent porta johns. I'd order 50-100 to be dropped at a 6 digit grid coordinate at a major dirt road intersection or such and we'd move them with tactical MHE and camo them up to hide them so they did not give away the camp from the air. The delivery/service guys could not read a map and did not know the grid system (and had a pretty regular turnover of employees) on one so I'd have to give classes to them every time we'd order them.

  We'd have designated admin times for the service trucks to come pump them and we'd provide a guide to escort the guy to where we had them placed/hidden then we'd have to rake out the tracks so the camp would be hidden from the air.

  I still have nightmares about Porta-Johns. On a big multi-service exercise not long before I got out the pumper truck died and the toilet were full and the medical gurus were threatening to shut down the exercise so the CG was chewing on my boss (the HQ Bn CO) and he was chewing on me. I told him the guy was a civilian and I could not shoot or court martial him and all I could do per the contract was refuse payment. The guy was trying and knew he would get the next award too as nobody else had the numbers we needed.

  BTW - you know the Soil Service people can provide Aerial Photos of your property which are also great tools. I had one of my place and when my son was a teenager he roosted some turkeys while bow hunting and we had an on-going Fall season and he was able to show me exactly which tree they were in and I got up the next morning and went up there and filled one as off the roost as soon as it got daylight.  

[peakbagger]

One of the many potential casualties of the Reagan Revolution was nearly all USGS maps. On the hit list to get rid of was the government wasting money printing all sorts of specialty maps including USGS quads. The concept was the government would still develop the database but if someone wanted a map they would have to buy it from private industry. Many folks depended on the USGS maps so a compromise was agree upon. Much of the rural areas of the US were still working on the series of 15 minute maps developed in the 1920s as they were the most recent. I was out bushwhacking mountains along the Canadian border in Maine and the most recent maps In the mid 1980s were dated 1921 showing roads and logging camps long gone. The compromise was that the USGS would stay in the map business until all the 7.5 minute quads were created and printed. That took a long time, well after Reagan retired and most forget about the deal. During this period, the government initially developed indexes of what the maps would be named and their catalog code long before the map actually existed and even when it was created and printed, their inventory records were not up to date. For a couple of years I would go in the index of future maps that were not supposed to exist and order them anyhow direct from the USGS and about 90% of the time they would ship me one. These were and still are labeled as provisional so they still have cartographer field notes but the topo was based on satellite data.  The other thing I learned from someone on the early internet was that anyone buying $500 worth of USGS maps was considered a dealer and got the maps for half price. Me and another person ended up buying two orders at half price and I still have that map collection. 

The papermill I worked for in NH was one of the suppliers of the map paper, it was high grade acid free paper designed to be folded and unfolded and printed with very stable ink. They still can get trashed if soaked for an extended period, but the ink does not run and usually if carefully unfolded and dried they are still legible. For a while various map dealers went to custom printed maps instead of keeping the USGS maps, they looked good when new but most were printed with lower grade paper and with an ink jet type ink. They rapidly broke down when wet and the ink would fade. 

It is pretty amazing the accuracy standards that were put in place for USGS maps considering most were made before Lidar.. Here are some details on the accuracy standards Map Accuracy Standards (usgs.gov)

I still tend to hike "old school" using maps and terrain features rather than the "follow the beep" GPS approach. There are hiking "lists" of high points that many people attempt to complete. The more obscure lists are to summits without trails. Pre GPS everyone ended up taking a slightly different route spreading out the use until the various routes converged near the top over the paths of least resistance. Now that GPS is so popular, folks either download tracks by folks who have done it previously or follow a route on a ap like Gaia. The result is the majority of the use is contrained to narrow track which quickly becomes a beaten down track. It has taken a lot of the challenge out of climbing those peaks. If folks lose their GPS devices or they stop working they usually get lost as in these rural areas, there may not be cell service. Some folks pay a subscription fee for devices that talk to satelites so they can text home and tell their spouse to call 911 and send the rescue team. There have even been cases where folks are lost and do have cell service and know their location but do not have a map so Fish and Game has to send a crew out to lead them out of the woods.  

[Old Greenhorn]

Interesting detail there Peak. Thanks for that. I too tend to rely on my map, a real map, not some digital thing. I have bought some topo's that lasted one day on the trails and flaked out when they got wet. Ticked me off because they still charged top dollar. I fold my maps for the days trip, so they get re-folded a lot. My habit was to buy two of each quad, one for the house and route planning, and one for my pack and use on the trail.
 I do love my maps and have a few on the wall that I refer to from time to time to figure things out. But they've been up there nearly 40 years now.

[caveman]

I appreciate the participation and education.  
6.  Was a submerged wooded swamp
7.  Intermittent stream (wet weather stream)  

TexasRanger, the map gets blurry when I blow it up also.  I had a lot of these maps laminated so that I could write on them with markers and erase my marks to reuse.  I've made several tests on some of these maps.  At one time, I was trying to teach my students with only one topo map.  

Later in the week I'll try to get some better map pictures and post a few more questions.  Others feel free to jump in and just add questions.  

[SwampDonkey]

What I used to go find at DNR was the cover type maps for areas I never hunted much on. They'd show me the roads, even the old grown in ones that I liked best, that were on clear cut hardwood forest. Those places always had grouse a plenty, fill your bag limit for that day. I always hunted on foot. Some people just drive all day on main logging roads and hardly see a bird.

[Texas Ranger]

Back when I was flying bugs I developed a folding map like we used in the service and could put a counties topo in my lap for flight and bug recording.  Basically, a four-color road map in grids that also showed woods.  Put them on a cloth and wax backing and a heat applied cover plastic that we could use over and over.  I think we used the same maps for years.

[SwampDonkey]

We laminated aerial photos here for the woodlot owner groups. Photos were always signed out for use in the woods. They might end up behind a pickup seat for a few weeks before coming back.........if the dog didn't it. :D  Anyway, we could mark them with grease pencil or marker for cruising and drawing in boundaries for sampling. Just rub off with a good white erasure. We used photos for ten years before the new updates came in. All the paper maps in the office where orthophotos. But not updated since 1983 or so, only the photos got updates. But those maps had property boundaries which never changed much. The photos were treated like a map, had scale and could draw the boundary on it from the orthophoto map. Not much for mountains here. I never saw a hill that couldn't be cut. Sometimes it depended on the approach, but it could be cut. :D