Site seems to run just fine but got LOTS of errors from http://validator.w3.org/check

Error Line 19, Column 8: element "header" undefined

<header>

✉

You have used the element named above in your document, but the document type you are using does not define an element of that name. This error is often caused by:
    incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Frameset" document type to get the "<frameset>" element),
    by using vendor proprietary extensions such as "<spacer>" or "<marquee>" (this is usually fixed by using CSS to achieve the desired effect instead).
    by using upper-case tags in XHTML (in XHTML attributes and elements must be all lower-case).
Error Line 22, Column 6: document type does not allow element "h1" here; missing one of "object", "applet", "map", "iframe", "button", "ins", "del" start-tag

  <h1>


✉

The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
Error Line 30, Column 7: element "nav" undefined

  <nav>

✉

You have used the element named above in your document, but the document type you are using does not define an element of that name. This error is often caused by:
    incorrect use of the "Strict" document type with a document that uses frames (e.g. you must use the "Frameset" document type to get the "<frameset>" element),
    by using vendor proprietary extensions such as "<spacer>" or "<marquee>" (this is usually fixed by using CSS to achieve the desired effect instead).
    by using upper-case tags in XHTML (in XHTML attributes and elements must be all lower-case).
Error Line 43, Column 11: element "section" undefined

  <section>


✉

The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
Error Line 54, Column 40: an attribute value literal can occur in an attribute specification list only after a VI delimiter

            <img src="img/bear.jpg" alt""> 

✉

Have you forgotten the "equal" sign marking the separation between the attribute and its declared value? Typical syntax is attribute="value".
Error Line 54, Column 41: end tag for "img" omitted, but OMITTAG NO was specified

            <img src="img/bear.jpg" alt""> 



✉

Have you forgotten the "equal" sign marking the separation between the attribute and its declared value? Typical syntax is attribute="value".
Error Line 82, Column 42: end tag for "img" omitted, but OMITTAG NO was specified

            <img src="img/relic.jpg" alt""> 



The mentioned element is not allowed to appear in the context in which you've placed it; the other mentioned elements are the only ones that are both allowed there and can contain the element mentioned. This might mean that you need a containing element, or possibly that you've forgotten to close a previous element.

One possible cause for this message is that you have attempted to put a block-level element (such as "<p>" or "<table>") inside an inline element (such as "<a>", "<span>", or "<font>").
Error Line 91, Column 9: name start character invalid: only S separators and TAGC allowed here

  </div id="wrapper">

✉
Error Line 92, Column 10: element "footer" undefined

  <footer>



You may have neglected to close an element, or perhaps you meant to "self-close" an element, that is, ending it with "/>" instead of ">".
Info Line 93, Column 54: start tag was here

     <li> 
        <a href="img/bear.JPG"> 
        <img src="img/bear.jpg" alt""> 
        <p>Bear Enjoying the day!</p>
       </a>
    </li>

     <li> 
        <a href="img/ike.JPG"> 
        <img src="img/ike.jpg" alt""> 
        <p>Ike Enjoying the day!</p>
       </a>
    </li>

     <li> 
        <a href="img/hammer1.JPG"> 
        <img src="img/hammer1.jpg" alt""> 
        <p>Hammer Enjoying the day!</p>
       </a>
    </li>

     <li> 
        <a href="img/ruger1.JPG"> 
        <img src="img/ruger1.jpg" alt""> 
        <p>Ruger Enjoying the day!</p>
       </a>
    </li>

     <li> 
        <a href="img/relic.JPG"> 
        <img src="img/relic.jpg" alt""> 
        <p>Relic Enjoying the day!</p>
       </a>
    </li>


  </ul>