How to Get the Scroll Bar with CSS Overflow on iOS

.scroll-container {
  width: 100%;
  padding-bottom: 30px;
  white-space: nowrap;
  overflow: auto;
  clip-path: inset(0 0 30px 0);
}

.item {
  display: inline-block;
  width: 150px;
  height: 300px;
  margin-right: 20px;
  background-color: #ddd;
  border-radius: 20px;
}

<div class="scroll-container">
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
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  <div class="item"></div>
  <div class="item"></div>
  <div class="item"></div>
</div>

How to get the scroll bar with CSS overflow on iOS

Edit following the comment left, kindly, by kritzikratzi:

[Starting] with ios 5beta a new property -webkit-overflow-scrolling: touch can be added which should result in the expected behaviour.

Some, but very little, further reading:

• Native momentum scrolling in iOS 5

Original answer, left for posterity.

Unfortunately neither overflow: auto, or scroll, produces scrollbars on the iOS devices, apparently due to the screen-width that would be taken up such useful mechanisms.

Instead, as you've found, users are required to perform the two-finger swipe in order to scroll the overflow-ed content. The only reference, since I'm unable to find the manual for the phone itself, I could find is here: tuaw.com: iPhone 101: Two-fingered scrolling.

The only work-around I can think of for this, is if you could possibly use some JavaScript, and maybe jQTouch, to create your own scroll-bars for overflow elements. Alternatively you could use @media queries to remove the overflow and show the content in full, as an iPhone user this gets my vote, if only for the sheer simplicity. For example:

<link rel="stylesheet" href="handheld.css" media="only screen and (max-device width:480px)" />

The preceding code comes from A List Apart, from the same article linked-to above (I'm not sure why they left of the type="text/css", but I assume there are reasons.

CSS - Overflow: Scroll; - Always show vertical scroll bar?

Just ran into this problem myself. OSx Lion hides scrollbars while not in use to make it seem more "slick", but at the same time the issue you addressed comes up: people sometimes cannot see whether a div has a scroll feature or not.

The fix: In your css include -

::-webkit-scrollbar {
  -webkit-appearance: none;
  width: 7px;
}

::-webkit-scrollbar-thumb {
  border-radius: 4px;
  background-color: rgba(0, 0, 0, .5);
  box-shadow: 0 0 1px rgba(255, 255, 255, .5);
}

/* always show scrollbars */
::-webkit-scrollbar {  -webkit-appearance: none;  width: 7px;}
::-webkit-scrollbar-thumb {  border-radius: 4px;  background-color: rgba(0, 0, 0, .5);  box-shadow: 0 0 1px rgba(255, 255, 255, .5);}

/* css for demo */
#container {  height: 4em;  /* shorter than the child */  overflow-y: scroll;  /* clip height to 4em and scroll to show the rest */}
#child {  height: 12em;  /* taller than the parent to force scrolling */}

/* === ignore stuff below, it's just to help with the visual. === */
#container {  background-color: #ffc;}
#child {  margin: 30px;  background-color: #eee;  text-align: center;}

<div id="container">  <div id="child">Example</div></div>